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Multiple Lung Cancer Genomic Projects Suggest New Targets, Research Directions for Non-Small Cell Lung Cancer

Curator, Writer: Stephen J. Williams, Ph.D.

UPDATED 08/11/2025

Human Curation vs. AI tools: ChatGPT & Knowledge Graphs [KG] Output: A case study for the following original curation:

  • Multiple Lung Cancer Genomic Projects Suggest New Targets, Research Directions for Non-Small Cell Lung Cancer

https://pharmaceuticalintelligence.com/2014/09/05/multiple-lung-cancer-genomic-projects-suggest-new-targets-research-directions-for-non-small-cell-lung-cancer/

 

This update was performed by the following methods:
A. GPT 5 Text analysis and Reasoning
B. Insertion of Knowledge Graph on topic Curation of Genomic Analysis from Non Small Cell Lung Cancer Studies  from Nodus Labs using InfraNodus software
C. Domain Knowledge Expert evaluation of the Update outcomes
This article has the following Structure:
Part A: Introduction to LLM, Knowledge Graph software InfraNodus, ChatGPT5 and Background Information on curated material for Test Case
Part B: InfraNodus Analysis of manual curation and Knowledge Graph Creation
Part C: Chat GPT 5 Analysis of Manually Curated Material
Part D: Curation entitled Multiple Lung Cancer Genomic Projects Suggest New Targets, Research Directions for Non-Small Cell Lung Cancer originally published on 09/05/2014
Results of Article Update with GPT 5
1. GPT5 alone was not able to understand the goal of the article, namely to determine knowledge gaps in a particular research area involving 5 genomic studies on lung cancer patients
2. GPT5 alone was not able to group concepts or comonalities between biological pathways unless supplied with a manually curated list of KEGG pathways from a list of mutated genes.  However this precluded any effect that fusion proteins had on the analysis and so GPT5 would only concentrate on mutated genes commonly found in literature
3. GPT was not able to access some of the open Access databases like NCBI Gene Ontology database
Results of Article Update with KnowledgeGraph presentation to GPT 5
4. As the Knowledge Graph understood the importance of fusion proteins and transversions, the knowledgegraph augmented the GPT analysis and so enriched the known pathways as well as could correctly identify the less represented pathways in the knowledge graph
5.  This led to the identification of many novel signaling pathways not identified in the original analysis, and was able to perform this task with ease and speed

6. GPT with InfraNodus Analysis was able to propose pertinent questions for future research (the goal of the original curation) such as:

  • How does the interaction between [[EGFR]] mutations and sex-specific gene alterations, including [[RBM10]], influence treatment outcomes in lung adenocarcinoma?
  • How does the intersection of mutational patterns from smoking influence pathway activation in NSCLC, and can identifying these interactions improve targeted therapy development?
Novelty in comparison to Original article published on 09/05/2014
7. it appears that manual curation is necessary to assist in the building of relevant knowledge graphs in the biomedical fields to augment generative AI analysis
8. by itself, generative AI is not optimized for inference of higher concepts from biomedical text, and therefore, at this point, requires the input from human curators developing domain-specific knowledge graphs
9.  The combination of ChatGPT5 and Knowledge graphs of this manually curated biomedical text added a further layer of complexity of gaps of knowledge not seen in the original curations including the need to study noncanonical signaling pathways like WNT and Hedgehog in smoker versus nonsmoker cohorts of lung cancer patients

A Comparison of Manual Expert-Curative and an LLM-based analysis of Knowledge Gaps  in Non Small Lung Cancer Whole Exome Sequencing Studies and a Use Case Example of Chat GPT 5

Part A: Introduction to LLM, Knowledge Graph software InfraNodus, ChatGPT5 and Background Information on curated material for Test Case

The development of Large Language Models (LLMs), together with development of knowledge graphs, have facilitated the ability to analyze text and determine the relationships among the various concepts contained within series of texts.  These concepts and relationships can be visualized, and new insights inferred from these visualizations.  As a result, this type of analysis suggests new directions and lines of research.

 

Alternatively,  these types of visualizations can also reveal gaps in knowledge which should be addressed. A new type of LLM and visualization tools have been developed to understand the gaps in knowledge in biomedical text.

Nodus Labs InfrNodus AI Knowledge Graph Software Tools Allow Text Relationship Visualization and Integrated AI Functionality

 

Infranodus makes knowlegde graphs from text and then is able to visualize the relationships between concepts (or nodes).  In doing so, the tool also highlights the various knowledge gaps (or large differences between nodes) which can be used to investigate new hypotheses and research directions of previously univestigated relationships between concepts.  This generates new research questions, in which these gaps can be used as prompts in the software’s integrated AI tool.  The AI tool, much like a GPT, returns recommendations for research to be conducted in the area.

https://infranodus.com/

In addition, the InfraNodus software can detect if text is too biased on a particular concept or conclusion, and using a GPT3 or GPT4, can determine if the nodes are too dispersed and will recommend which gaps should be focused on.

The software can upload any biomedical text in various formats

A full demonstration is on their website but a good summary is found on their Youtube site at

https://www.youtube.com/watch?v=wCEhiIJsmrg

A couple of use cases include

 

 

Previously we had manually curated and analyzed the knowledge gaps from a series of publications on whole exome sequencing  of biopsied tumors from cohorts of non small lung cancer patients. This curation (from 2016) is seen in the lower half of this updated link below and I separated with a bar and highlighted in Yellow as Text for AI Analysis.

https://pharmaceuticalintelligence.com/2014/09/05/multiple-lung-cancer-genomic-projects-suggest-new-targets-research-directions-for-non-small-cell-lung-cancer/

A literature analysis of the driver mutations found in five NSLC exome sequencing projects:

  1. Comprehensive genomic characterization of squamous cell lung cancersNature 2012, 489(7417):519-525.
  2. A genomics-based classification of human lung tumorsScience translational medicine 2013, 5(209):209ra153.
  3. Govindan R, Ding L, Griffith M, Subramanian J, Dees ND, Kanchi KL, Maher CA, Fulton R, Fulton L, Wallis J et alGenomic landscape of non-small cell lung cancer in smokers and never-smokersCell 2012, 150(6):1121-1134.
  4. Imielinski M, Berger AH, Hammerman PS, Hernandez B, Pugh TJ, Hodis E, Cho J, Suh J, Capelletti M, Sivachenko A et alMapping the hallmarks of lung adenocarcinoma with massively parallel sequencingCell 2012, 150(6):1107-1120.
  5. Peifer M, Fernandez-Cuesta L, Sos ML, George J, Seidel D, Kasper LH, Plenker D, Leenders F, Sun R, Zander T et alIntegrative genome analyses identify key somatic driver mutations of small-cell lung cancerNature genetics 2012, 44(10):1104-1110.

 

were performed.

The purpose of this analysis was to uncover biological functions related to the sets of mutated genes with limited research publications in the area of  non small cell lung cancer.  The identification of such biological functions would represent a gap in knowledge in this disease.  In addition, this analysis attempted to find new lines of research or potential new biotargets to investigate for lung cancer therapy.

 

 

 

However this manual method is time consuming and may miss relationships not defined in a GO ontology or gene knowledgebases.

Therefore we turned to an AI-driven approach:

  1. Using InfraNodus ability to develop a knowledge graph based on our curation and determine if the AI platform could infer knowledge gaps
  2. Utilize Chat GPT5 to analyze the same curated set to determine if OpenAI analysis would lead to the similar analysis from curated material
  3. Determine if combining a knowledge graph within GPT would lead to a higher level of analysis

See below (Part D) of this update for the curated studies which were included in this analysis and the text which was entered into both InfraNodus and Chat GPT5. 

As a summary, it seems that manual curation is necessary to assist in the building of relevant knowledge graphs in the biomedical fields to augment generative AI analysis.  In addition, it appears that , by itself, generative AI is not optimized for inference of higher concepts from biomedical text, and therefore, at this point, requires the input from human curators developing domain-specific knowledge graphs.

 

Part B. InfraNodus Analysis of manual curation and Knowledge Graph Creation

Methods: 

Text of the curation was copied and directly pasted into the text analysis module of InfraNodus.  There was no editing of words however genes in the curation were linked to their GeneCard entry. GeneCards is a database run by the Weizmann Institute.  InfraNodus utilizes a combination of LLMs and its own GraphRAG system to provide insights from text analysis. While it leverages various models, including those from OpenAI and Anthropic, it’s not limited to a single LLM. Instead, InfraNodus integrates these models within its GraphRAG framework, which enhances their capabilities by adding a relational understanding of the context through a knowledge graph.

InfraNodus then autogenerates a knowledge graph and returns entities and relationships between entities.  InfraNodus offers the opportunity to modify the knowledge graph however for this analysis we used the first graph InfraNodus generated.  Inspection of this graph (as shown below) was deemed reasonable.

 

Results

The knowledge graph of the input text is shown below:

InfraNodus generated Knowledge Graph of 5 WES Non Smal Cell Lung Cancer studies involving smokers and non smokers

 

Four main concepts were returned: tumors, genes, literature, and mutations.

A snapshot of the Analysis window is given below.  It should be noted that InfraNodus felt there needed to be more connections between Pathway and Mutational Patterns.

An InfraNodus reposrt with Knowlege Graph on Whole Exome Sequencing studies in NSCLC to determine mutational spectrum in smokers versus non smokers

Auto generated summary report

Context name: text_250808T0144

Created on: aug 7, 2025 9:47 pm

Last updated on: aug 7, 2025 10:10 pm

Main concepts:

[[tumors]], analysis, [[mutations]], identify, [[lung]], [[genes]]

Main topics:

  1. Tumor Genomics: [[tumors]] [[lung]] reveal
  2. Genetic Alterations: identify [[genes]] study
  3. Pathway Analysis: analysis pathway literature
  4. Mutation Patterns: [[mutations]] [[egfr]] [[rbm10]]

Structural gap (topics to connect):

  1. Pathway Analysis: analysis pathway
  2. Smoking Influence: mutational [[smoking]]

Topical connectors:

alk clinical [[egfr]] mutational pathway [[paper]] found key literature study [[genomic]] reveal [[transversion]]

 

Top relations / ngrams:

1) [[lung]] [[tumors]]

2) alk fusion

3) link function

4) eml alk

5) function [[gene_ontology]]

Modulary: 0.47

Relations:

InfraNodus identified 744 relations between entities (nodes)

A list of some of the more frequent are given here:

source target occurrences weight betweenness
[[lung]] [[tumors]] 8 24 0.4676
analysis pathway 5 12 0.2291
significantly [[genes]] 5 9 0.1074
significantly [[mutated]] 4 12 0.0281
[[mutated]] [[genes]] 4 12 0.0847
[[transversion]] high 3 12 0.0329
[[smoking]] history 3 10 0.0352
study identify 3 9 0.2051
mutational pattern 3 9 0.0921
[[rbm10]] [[mutations]] 3 8 0.1776
literature analysis 3 7 0.2218
[[egfr]] [[mutations]] 3 7 0.2139
[[transversion]] group 3 7 0.0259
enriched cohort 3 6 0.0219
[[whole_exome_sequencing]] [[tumors]] 3 6 0.3485
identify [[genes]] 3 6 0.2268
including analysis 3 5 0.1985
alteration [[genes]] 3 4 0.1298
[[tumors]] analysis 3 4 0.5192
alk fusion 2 15 0.0671
link function 2 14 0.0269
function [[gene_ontology]] 2 13 0.0054

 

Notice how the betweenness or importance of connection of disparate concepts vary but are high between concepts like tumors and analysis, or lung and tumor, however many important linked concepts like alk and fusion may have low betweenness but are mentioned frequently and have a much higher weight or closeness to each other. Gene-mutations-transversions-smoking seem to have a high correspondence to each other

For a full list please see the file

InfraNodus relations five WES studies on NSCLC and smoking

sjwilliams_text_250808T0144_nodedataon NSCLCWESstudies

Generated the following responses using AI to bridge the gap between

  1. Mutation Patterns: [[mutations]][[egfr]][[rbm10]]and
  2. Genetic Alterations: identify[[genes]]study:The recent comprehensive studies on lung adenocarcinoma have significantly advanced our understanding of the genetic landscape by identifying key mutations and their intricate interactions. Notably, EGFR and RBM10 exhibit distinct mutational patterns, with RBM10 inactivations being notably enriched in male cohorts. This gender-linked enrichment underscores a potential differential oncogenic pathway involving ERBB2 and RB1 alterations.Moreover, these projects emphasize the quest to map significant gene alterations within lung adenocarcinoma. The identification of such genes not only corroborates prior reports but also expands upon them by highlighting new connections between mutation signatures and clinical factors like smoking history. These findings are crucial as they can inform future therapeutic targeting strategies, ensuring that personalized treatment approaches consider both gender-specific genomic enrichments and mutation-driven tumorigenesis pathways elucidated through rigorous analyses.elaborate

 

<MainTopics>

  1. Tumor Genomics: [[tumors]], [[lung]], reveal, base, [[genomic]], [[data]], classification, subtype,
  2. Genetic Alterations: identify, [[genes]], study, alteration, reported, significantly, [[lung_adenocarcinoma]], key,
  3. Pathway Analysis: analysis, pathway, literature, including, activation, target, [[nsclc]], [[patients]],
  4. Mutation Patterns: [[mutations]], [[egfr]], [[rbm10]], male, enriched, cohort, [[erbb2]], noted,
  5. Smoking Influence: mutational, [[smoking]], [[transversion]], pattern, high, notably, [[smokers]], show,
  6. Research Strategies: found, [[paper]], [[omics]], unique, profile, result, multus, characterization,
  7. Targeted Therapy: alk, [[lung_cancer]], fusion, [[therapy]], ro, eml, include, targeted,
  8. Mutation Signatures: clinical, [[tumor]], approach, mutation, sample, signature, gender, specific,
  9. Gene Function: link, [[gene]], note, function, author, [[gene_ontology]],

</MainTopics>

 

<TopicalGap>:

  1. Genetic Alterations: identify [[genes]]
  2. Mutation Patterns: [[mutations]] [[egfr]]

</TopicalGap>

 

 

questions generated using AI to help you explore “alk, clinical, [[egfr]], mutational, pathway, [[paper]], found, key, literature, study, [[genomic]], reveal, [[transversion]]…”:How do mutational patterns, specifically EGFR mutations and transversions related to smoking history, influence the effectiveness of targeted therapies in NSCLC patients?elaborate

 

ideas generated using AI to help you explore “alk, clinical, [[egfr]], mutational, pathway, [[paper]], found, key, literature, study, [[genomic]], reveal, [[transversion]]…”:Develop a predictive model that utilizes genomic data and smoking history to forecast patient response to targeted therapies. This model would identify key mutational signatures linked to EGFR and other genes, highlighting the impact of smoking-induced transversions on drug efficacy.elaborate

 

Project Notes

 

The recent comprehensive studies on lung adenocarcinoma have significantly advanced our understanding of the genetic landscape by identifying key mutations and their intricate interactions. Notably, EGFR and RBM10 exhibit distinct mutational patterns, with RBM10 inactivations being notably enriched in male cohorts. This gender-linked enrichment underscores a potential differential oncogenic pathway involving ERBB2 and RB1 alterations.

 

Moreover, these projects emphasize the quest to map significant gene alterations within lung adenocarcinoma. The identification of such genes not only corroborates prior reports but also expands upon them by highlighting new connections between mutation signatures and clinical factors like smoking history. These findings are crucial as they can inform future therapeutic targeting strategies, ensuring that personalized treatment approaches consider both gender-specific genomic enrichments and mutation-driven tumorigenesis pathways elucidated through rigorous analyses.”

 

<ConceptualGateways>

alk

clinical

[[egfr]]

mutational

pathway

[[paper]]

found

key

literature

study

[[genomic]]

reveal

[[transversion]]

</ConceptualGateways>

 

 

How do mutational patterns, specifically EGFR mutations and transversions related to smoking history, influence the effectiveness of targeted therapies in NSCLC patients?

 

The report from the NCI Bulletin outlines significant advancements in understanding lung cancer through genome sequencing projects. These studies have revealed a plethora of genetic and epigenetic alterations across various forms of lung tumors, including adenocarcinomas, squamous cell carcinomas, and small cell lung cancers. Notably, some identified alterations could be targeted by existing therapies, providing potential new avenues for treatment.Dr. Meyerson emphasizes the complexity of these genetic changes, highlighting that distinct mechanisms inactivating genes can vary between tumors. The report also notes gaps in knowledge regarding non-coding DNA alterations, which comprise a major part of the human genome.Key findings include:1. Comprehensive genomic analyses revealing unique driver mutations in lung adenocarcinoma, such as those affecting MET and ERBB2, alongside significant mutations in known cancer drivers like TP53 and KRAS.2. A classification system based on genomic data enabling more accurate patient stratification—achieving a 75% classification rate of lung cancer subtypes.3. Smoking history is shown to influence mutational patterns significantly, with smokers exhibiting a higher incidence of point mutations compared to never-smokers.Moreover, the integration of genomic data and pathway analysis highlighted recurrent mutations across various pathways related to tumorigenesis, suggesting new therapeutic targets and underscoring the importance of personalized medicine approaches that factor in gender-specific mutation distributions.This synthesis of findings not only corroborates earlier studies but also extends our understanding of the interplay between genomic alterations, smoking habits, and clinical outcomes in lung cancer. Future research is needed to explore the implications of these findings further and to develop targeted therapies that leverage the identified genetic alterations.

 

  1. Tumor Genomics
  2. Genetic Alterations
  3. Pathway Analysis
  4. Mutation Patterns

 

Main Ideas Summary from Infranodus:

 

The report from the NCI Bulletin highlights significant developments in lung cancer genomics through five genome sequencing projects. These studies have uncovered various genetic and epigenetic alterations across multiple forms of lung cancer, including adenocarcinomas, squamous cell cancers, and small cell lung cancers. Notably, these alterations may correspond to existing drugs, offering new avenues for targeted therapy.

Key findings include the identification of unique mutations in genes like NF1, MET, and ERBB2, with particular attention to smoking’s role in mutational patterns. The analysis shows that smokers exhibit a higher incidence of specific point mutations, marking a distinct divergence in mutation profiles compared to never-smokers.

The research also emphasizes the need for continued exploration of the data to link mutation signatures with clinical outcomes, particularly regarding gender-specific differences in mutation prevalence. Emerging insights suggest that pathways involving MYC and alterations in splicing factors could be vital targets for future therapeutic strategies.

Overall, the studies collectively underscore an urgent need for integrating genomic data into clinical practice, which can lead to more personalized treatment approaches for lung cancer patients by considering both the genetic landscape of tumors and their histories, such as smoking exposure. The ongoing efforts to map gene alterations within lung adenocarcinoma not only reinforce existing knowledge but also reveal new potential therapeutic targets that can significantly impact patient outcomes.

 

Questions to Explore from InfraNodus:

 

How does the interaction between [[EGFR]] mutations and sex-specific gene alterations, including [[RBM10]], influence treatment outcomes in lung adenocarcinoma?

 

 

How does the intersection of mutational patterns from smoking influence pathway activation in NSCLC, and can identifying these interactions improve targeted therapy development?

 

Part C: Chat GPT 5 Analysis of Manually Curated Material

Now let us see how Chat GPT5 analyzed the same material.

Methods

 

Nice — I’ll work from the KEGG-pathway list shown in your text (the table of pathways with PubMed counts) and call out major KEGG pathways that are not represented there.

Important caveat: “Not represented in the table” below means not listed in the KEGG-pathway hits shown in your pasted literature analysis, not that these pathways never play a role in lung cancer. Absence from that table can reflect lack of reporting in the specific WES/WGS studies or the PubMed keyword search used — it’s not proof the pathway is uninvolved biologically.

The above Important caveat was very important because it showed that ChatGPT5 could understand what my experimental goals were, or at least understood the problem I was presenting to ChatGPT5!

Major KEGG pathways missing from the provided KEGG list

 

(However Note that GPT did NOT take into account the mutational spectrum of the studies or the gene lists supplied in the curation)

 

These are commonly cited cancer-related KEGG pathways that do not appear in the table you gave:

  • Wnt signaling pathway
  • Notch signaling pathway
  • Hedgehog signaling pathway
  • TGF-beta signaling pathway
  • Hippo signaling pathway
  • p53 signaling pathway(note: TP53 is mutated in many tumors, so p53 biology is implicated in the text, but “p53 signaling” does not appear in that KEGG hits table)
  • Apoptosis (intrinsic/extrinsic apoptotic pathways)
  • Autophagy
  • NF-kappa B signaling pathway
  • Ubiquitin-mediated proteolysis / proteasome
  • DNA repair pathways (several separate KEGG entries):
    • Homologous recombination
    • Mismatch repair
    • Nucleotide excision repair
    • Base excision repair
    • Fanconi anemia pathway
  • Cellular metabolism pathways commonly in cancer:
    • Glycolysis / Gluconeogenesis
    • Citrate cycle (TCA cycle) / Oxidative phosphorylation
    • Fatty acid metabolism / beta-oxidation
    • Pentose phosphate pathway
  • Immune-signaling / antigen processing:
    • T cell receptor signaling pathway
    • B cell receptor signaling pathway
    • Antigen processing and presentation
  • Autocrine/paracrine inflammation/chemokine signaling beyond the one low-count entry (general cytokine networks other than the single “cytokine–cytokine receptor interaction” hit)
  • Signal transduction modules sometimes separate in KEGG:g. Calcium signaling was listed in your table, but other modules like cGMP–PKG signaling or PKA/PKC broader signaling networks are not.

 

Quick summary

The KEGG table in your text highlights many cancer and receptor-tyrosine/MAPK/PI3K related pathways (cell cycle, MAPK, ErbB, JAK-STAT, focal adhesion, etc.). What’s not listed are numerous developmental morphogen pathways (Wnt/Notch/Hedgehog/TGF-β/Hippo), many DNA-repair and core metabolic pathways, canonical apoptosis/autophagy/ubiquitin pathways, and broad adaptive-immune signaling pathways.

If you want, I can:

  • (A) cross-check this against the full KEGG pathway list and produce a definitive “KEGG universe → present vs absent in your table” spreadsheet, or
  • (B) prioritize which of the missing pathways you’d most want investigated in lung tumor sequencing data and suggest genes to look for.

Which follow-up would you prefer?

 

Now taking out the KEGG list I gave GPT in order to force GPT to do a similar but unbiased analysis

 

From the studies you’ve shared, we can identify which KEGG pathways are under-represented (i.e., appear less frequently altered than expected) in the altered genes in lung cancer.

To do this, we note that the researchers used KEGG and other pathway analysis tools (PathScan, literature curation, proteomics) to see which biological pathways the mutated genes mapped to.
While many well-known cancer pathways were found to be activated (MAPK, PI3K-AKT, mTOR, cell cycle, oxidative stress, etc.), a few key pathways were reported as unexpectedly low in mutation frequency despite their known role in cancer biology.

KEGG Pathways Under-Represented in Altered Genes in Lung Cancer

From the descriptions in Papers 1–5, these are the main pathways that appear under-represented:

  1. MAPK signaling pathway
    • Normally, MAPK is a major cancer driver pathway. In this dataset, MAPK activity was high in proteomics, but many tumors lacked mutations in MAPK pathway genes.
    • This means MAPK activation is often non-mutational (possibly via upstream signaling, epigenetic changes, or ligand activation), so in mutation-based KEGG enrichment it is under-represented.
  2. PI3K-Akt signaling pathway
    • Like MAPK, the PI3K-Akt pathway was highly activated in proteomics, but often without mutations in PI3K pathway genes.
    • Under-represented in gene mutation lists, despite strong functional activation.
  3. mTOR signaling pathway
    • Functional activation was observed (especially when STK11 was mutated), but most tumors had no mTOR-pathway gene mutations.
    • Under-represented when looking only at altered genes.
  4. JAK-STAT signaling pathway
    • Mentioned as novel pathway alterations in some tumors, but in KEGG enrichment analysis, JAK-STAT genes did not appear as a dominant mutated group—implying low mutation frequency compared to other cancer types.
  5. Oxidative phosphorylation & metabolic pathways
    • While oxidative stress response genes (e.g., KEAP1) were sometimes mutated, the oxidative phosphorylation KEGG pathway itself did not emerge as mutation-enriched, suggesting functional changes occur via other mechanisms (e.g., hypoxia signaling).
  6. Histone modification / chromatin remodeling pathways
    • While some epigenetic regulators (ARID1A, CREBBP, EP300, MLL) were mutated, KEGG’s “Chromatin remodeling” and “Histone modification” groupings were less represented than expected given the role of epigenetics in lung cancer, indicating epigenetic dysregulation is often non-mutational.

Why They Are Under-Represented

  • Proteomics revealed activation without DNA mutation (e.g., ligand-driven activation, phosphorylation cascades).
  • Epigenetic or post-translational modifications can activate pathways without altering the coding sequence.
  • Tumor heterogeneity: some pathways are only altered in subsets of tumors and thus don’t reach statistical enrichment.
  • Limitations of mutation-based KEGG analysis: pathways that are activated downstream or by non-coding alterations are missed.

Summary Table

Pathway (KEGG ID) Representation in Mutated Genes Reason for Under-Representation
hsa04010 MAPK signaling Low Activated via non-mutational mechanisms
hsa04151 PI3K-Akt signaling Low Functional activation w/o gene mutations
hsa04150 mTOR signaling Low Activation often via upstream STK11 loss or growth factor signaling
hsa04630 JAK-STAT signaling Low Rarely mutated, altered mostly via cytokine/growth factor changes
hsa00190 Oxidative phosphorylation Low Functional metabolic shift via hypoxia & ROS stress, not mutations
Chromatin remodeling / histone modification Low Mostly altered via epigenetic changes, not coding mutations

If you want, I can cross-reference the exact KEGG IDs and run a quick gene-to-pathway mapping using the genes listed in the reports so we can get a precise statistical under-representation list. That way it’s backed by an enrichment p-value rather than just qualitative observation.

 

I tried to re-run the KEGG-backed analysis you requested, but the KEGG REST endpoints/web pages aren’t reachable from my browsing tool right now (the web.run calls to KEGG returned an internal/safety error). I can’t produce a properly-sourced, KEGG-ID–backed enrichment report unless I can successfully query KEGG (or a comparable pathway service) for the exact pathway membership.

Two clear, immediate options — tell me which you prefer and I’ll proceed right away:

Option 1 — Proceed with a KEGG-backed run using an alternate route (recommended)
I’ll attempt a small number of web.run search queries (to public pathway tools that mirror KEGG membership, e.g., g:Profiler / Reactome / Enrichr / DAVID) and then follow links to KEGG pathway pages. This often works even when direct KEGG REST calls fail. It will take a few web.run calls and I’ll cite the pages used. (If you want me to prefer a particular service — e.g., g:Profiler, Enrichr, DAVID — say so; otherwise I’ll pick g:Profiler as it’s robust.)

Option 2 — Run an immediate local (best-effort) analysis without web lookups
I’ll map the genes you listed to likely KEGG pathways from internal knowledge, run hypergeometric enrichment using a standard human background (20,000 genes), and give a ranked list of under-represented KEGG pathways with p-values — but I must be clear this is approximate (I cannot provide verified KEGG IDs or exact pathway sizes).

If you pick Option 1, I’ll start the web lookups now and produce the KEGG-ID mapped, statistically precise under-representation list with citations.
If you pick Option 2, I’ll run the approximation immediately and give results plus a confidence caveat.

Which do you want?

Sources

Ask ChatGPT

You said:

Use Option 1 to Proceed with a KEGG-backed run using an alternate route

ChatGPT said:

Thought for 37s

Thanks — I followed Option 1 trying to do a KEGG-backed run, but hit the same problem: my web tool (web.run) can reach g:Profiler/KEGG reliably in some contexts but it failed for the programmatic queries I attempted (internal / non-retryable errors). Because you explicitly requested a KEGG-backed run, I tried an alternate route (g:Profiler web query) and the site blocked the automated call.

Rather than leave you waiting, I made a transparent, reproducible best-effort analysis right now so you have immediate, concrete results — but please read the very important limitations below before using these numbers: (GPT having problems accessing material behind firewalls and paywalls)

What I did (short)

  1. I extracted a conservative set of 48 unique genes from the papers you supplied (recurrent drivers, fusion partners, and the druggable gene list).
    Gene list used (48 genes):
    TP53, KRAS, EGFR, STK11, KEAP1, SMARCA4, RBM10, NF1, MET, ERBB2, RIT1, BRAF, PIK3CA, PTEN, ARID1A, U2AF1, CREBBP, EP300, MLL, ALK, ROS1, DACH1, CFTR, RELN, ABCB5, HGF, JAK2, JAK3, HDAC2, HDAC6, HDAC9, BIRC6, ITGB1, ITGB3, MMP2, PRKCB, PIK3CG, TERT, MMP14, AURKC, ERBB4, FGFR1, EML4, SIK2, ZFHX4, EPHA3, EPHA7, SLIT2.
  2. Because direct KEGG lookups failed, I mapped those genes to a short list of common KEGG pathways by manual curation (based on canonical pathway membership knowledge) and used conservative, literature-style approximate pathway sizes (number of genes in that KEGG pathway) to compute exact hypergeometric lower-tail p-values (i.e., probability of observing as few or fewer genes in the pathway than we did — an under-representation test).
  3. I computed exact hypergeometric probabilities (sum of combinations) with a standard human gene background of N = 20,000. All calculations were executed programmatically (so no hand-approximate combinatorics).

Important limitations (please read)

  • This is NOT a true KEGG-backed run. I could not fetch KEGG pathway membership lists or KEGG IDs because the web tool could not access the KEGG/g:Profiler APIs in this session. (more GPT issues with access to data)
  • I used manually mapped genes → pathways (conservative, but not exhaustive) and approximate pathway sizes (estimates). Because both gene membership and exact pathway sizes matter a lot for enrichment statistics, the p-values below are illustrative only — they are useful to prioritize where to retry a proper KEGG query, but should not be taken as authoritative.
  • The correct, defensible way to produce what you asked is to re-run this on g:Profiler/Enrichr/DAVID (or download KEGG GMTs) so pathway membership and KEGG IDs are exact. I can do that as soon as the web tool can access those services (or you can paste exact KEGG gene sets if you prefer).

Results — immediate best-effort under-representation test

Analysis parameters

  • Number of input genes (n): 48
  • Background gene universe (N): 20,000 (standard approximation)
  • For each pathway I show: pathway size (K, approximate), number of genes from your list found in that pathway (k), and the hypergeometric lower-tail p-value P(X ≤ k) (probability of seeing k or fewer pathway genes by chance). Lower p-values (e.g., < 0.05) would suggest significant under-representation.
Pathway (approx KEGG) Pathway size K (approx) Genes found (k) Lower-tail p-value P(X ≤ k)
MAPK signaling (hsa04010) 270 10 0.9999999999678
PI3K-Akt signaling (hsa04151) 350 7 0.9999983354944
mTOR signaling (hsa04150) 120 3 0.9998044249093
JAK-STAT signaling (hsa04630) 150 3 0.9995423622408
Oxidative phosphorylation (hsa00190) 130 0 0.7309662417384
Spliceosome (hsa03040) 120 2 0.9970072261351
Chromatin / epigenetic regulators (KEGG-like grouping) 200 5 0.9999919751398
ECM / focal adhesion (hsa04510 / related) 150 4 0.9999706923476
Cell cycle (hsa04110) 200 3 0.9986613990288

Interpretation: none of the pathways above reach statistical significance for under-representation under the assumptions I used. The closest to a (moderate) signal is oxidative phosphorylation where we observed 0 genes from the list (p ≈ 0.73) — but that p-value is still far from being significant (p < 0.05 would be needed). In short: no pathway is robustly under-represented in this small gene set using the conservative approximations above.

What I recommend (next steps to get the exact KEGG-ID–backed answer you originally asked for)

  1. Allow me to retry the web-backed run (g:Profiler / Enrichr / DAVID) — I’ll re-run the enrichment and return:
    • gene → exact KEGG IDs mapping,
    • KEGG pathway sizes (exact K),
    • over- and under-representation p-values (Fisher/hypergeometric), and
    • multiple-testing corrected q-values (Benjamini–Hochberg).
      (This requires the web tool to be able to reach g:Profiler/KEGG; I already tried and the call failed. If you want, I’ll attempt again immediately.)
  2. If you prefer not to rely on the web tool, you can paste your final canonical gene list (e.g., a CSV of the exact genes you want analyzed) and I will run a conservative local analysis like the above but I will be explicit that KEGG IDs and pathway sizes are approximations.
  3. If you’d like, I can also send you the exact code/notebook I used for the above best-effort run so you (or your bioinformatics person) can re-run it locally against an up-to-date KEGG GMT file.

If you want me to retry the web-backed run now, say “Retry web run now” and I’ll immediately attempt g:Profiler/Enrichr again and produce the precise KEGG-ID–backed enrichment with citations. If you prefer I proceed without web access (i.e., run a local approximation on a larger set of genes or with different pathway groupings), tell me what gene list to use and I’ll compute immediately.

Top of Form

 

Bottom of Form

 

Done — I created a bar chart showing estimated PubMed article counts (prior to 2018) for “lung cancer” mentions of the pathways we discussed: MAPK, PI3K-Akt, mTOR, JAK-STAT, and Oxidative phosphorylation.

Important caveats (please read)

  • I could not access PubMed programmatically from this session (the web tool failed on PubMed/NCBI requests), so the numbers used are illustrative estimates, not exact counts.
  • If you need exact PubMed counts (filtered to publications before 2018), I can re-run the web-backed PubMed queries and regenerate the graph as soon as web access to NCBI is available — just say “Retry PubMed queries” and I’ll attempt that immediately.
  • The image file is available to download: Download the bar chart image.

If you want, I can:

  • Re-run the exact PubMed queries and update the chart with real counts, or
  • Expand the chart to include more pathways (e.g., chromatin modifiers, spliceosome, cell cycle), or
  • Provide the code/notebook used so you can run it locally against PubMed.

 

Here’s the expanded bar chart with additional pathways — Spliceosome, Chromatin remodeling / histone modification, ECM / focal adhesion, and Cell cycle — alongside the original set.

You can download the image here: Download expanded chart.

Would you like me to now replace these illustrative numbers with exact PubMed counts (filtered to before 2018) by running targeted PubMed searches?

 

 

Yes — even though the dataset and pathway lists we discussed focused mostly on signaling, metabolic, and genomic alterations, there is a clear immune component to lung cancer supported by both your provided text and the broader literature. (Now note that GPT noticed a clear literature coverage of cell cycle in lung cancer however it is claiming there was evidence of an immune component in the literature before 2018).

Evidence from your provided studies (Note GPT is using recent evidence not just restricting to periods before 2018)

  1. Pathways with immune relevance
    • JAK-STAT signaling (detected in the analysis)
      • Central to cytokine signaling, immune cell activation, and inflammatory responses in the tumor microenvironment.
      • Altered JAK-STAT can drive immune evasion or chronic inflammation that promotes tumor growth.
    • RTK/RAS/RAF pathway indirectly affects immune signaling by altering cytokine/chemokine secretion from tumor cells.
    • ROS1-ALK fusions
      • These can alter the tumor’s immunogenic profile; your text notes they may create epitopes that make tumors amenable to immunotherapy.
    • Chromatin remodeling / epigenetic regulators
      • Affect antigen presentation (MHC gene expression) and immune checkpoint ligand expression.
  1. Fusion proteins and immune sensitivity
    • The EML4–ALK fusion cohort:
      • Shown in cited literature to be less chemosensitive but potentially sensitive to immune-based approaches when certain epitopes are exposed.
      • Also exhibit HSP90 chaperone dependence, which links to immune stress response pathways.
  1. Tumor heterogeneity and immune escape
    • The genomic heterogeneity reported (monoclonal vs biclonal tumors) suggests different subclones may evade immune surveillance differently — a hallmark of tumor–immune system interaction.

From broader lung cancer research

Even when not highlighted in mutation frequency lists, immune-related processes in lung cancer are driven by:

  • Tumor-infiltrating lymphocytes (TILs) and their exhaustion profiles.
  • Immune checkpoints (PD-1/PD-L1, CTLA-4) — a major therapeutic target in NSCLC.
  • Inflammatory cytokine networks (many driven via JAK-STAT, NF-κB, MAPK cross-talk).
  • Neoantigen load (especially in smokers, due to high mutation rates) that can trigger immune recognition — unless suppressed by tumor-mediated immunosuppression.

Conclusion

Yes — there is an immune component to lung cancer.
It may not appear as strongly in mutation-based KEGG under-representation analysis (because immune evasion is often mediated by gene expression, epigenetics, and tumor–immune interactions rather than recurrent coding mutations), but immune signaling pathways like JAK-STAT and cytokine-related signaling are still altered and clinically relevant.

 

(Remember our initial test was to see if GPT could do our manual curative analysis without relying on current information!)

That’s why immune checkpoint inhibitors (anti–PD-1, anti–PD-L1, anti–CTLA-4) are now standard-of-care in many lung cancer treatment regimens (The evidence that led to immune checkpoint inhibitors was not based just on JAK-STAT or cytokine signaling).

 

Now Let Us See What Happens When a Knowledge Graph from InfraNodus is Imported into Chat GPT5

 

The import of a knowledge graph as a CSV from InfraNodus into ChatGPT5 is rather straightforward as can directly upload into the GPT interface.

 

ChatGPT was prompted with: “based on the imported knowledge graph tell me what Gene ontology biologic functions are missing?

ChatGPT said:

Your imported graph isn’t labeled with standard Gene Ontology (GO) IDs or names, so I can’t directly map it to “biological process” terms yet.

The next step is to align your node name column with the official GO Biological Process ontology and then report which expected functions are missing.

I can:

  1. Pull the latest GO Biological Process list.
  2. Match your nodes against it.
  3. Output the GO BP terms absent from your network.

Do you want me to fetch the current GO BP ontology from the Gene Ontology database and run that comparison?

You said:

based on the imported knowledge graph tell me what KEGG processes are missing?

ChatGPT said:

To identify which KEGG processes are missing from your imported knowledge graph, the first step is to retrieve an up-to-date list of KEGG human pathways and then compare that against the nodes present in your graph. Here’s how I can help:

  1. Fetch the current list of KEGG human pathways

I can pull the latest catalog of KEGG pathways for Homo sapiens, which includes major metabolic routes (e.g., purine metabolism, glycolysis) as well as signaling pathways (e.g., JAK-STAT, Wnt, PI3K-Akt) KEGG+1.

  1. Compare with your knowledge graph nodes

Once I have that KEGG list, I’ll match it against your graph’s node name entries. Any pathway names or identifiers (like hsa04110 for “Cell cycle”) not present in your graph would be flagged as missing.

  1. Deliver the findings

I’ll provide you with:

  • A list of KEGG processes present in your graph
  • A list of those missing, enabling you to fill in gaps or trigger further investigation

Does that sound good? If you’d like, please share a sample or the full list of your graph’s node name entries, especially if they include KEGG-style labels or pathway names—it’ll help speed up the matching process.

Sources

You said:

Fetch the current list of KEGG human pathways and compare with my knowledge graph nodes and provide me with a list of KEGG processes present and a list of KEGG processes missing.

ChatGPT said:

I’ve fetched the current list of KEGG human pathways (hsa) and compared it to the nodes in your imported knowledge graph. Here’s what we can do next—and what I need from you to complete the analysis:

KEGG Human Pathway List

Below are just a few highlights from the complete KEGG human pathway list (retrieved via KEGG REST /list/pathway/hsa) rest.kegg.jp:

  • hsa00010 – Glycolysis / Gluconeogenesis
  • hsa00020 – Citrate cycle (TCA cycle)
  • hsa01100 – Metabolic pathways
  • hsa04010 – MAPK signaling pathway
  • hsa04151 – PI3K-Akt signaling pathway
  • hsa04910 – Insulin signaling pathway
  • hsa05200 – Pathways in cancer
  • …plus hundreds more spanning metabolism, genetic information processing, organismal systems, disease, and more.

You can view the full list in the KEGG API or in your local copy if you’ve grabbed it via /list/pathway/hsa.

What I Need From You

To identify which KEGG pathways are present or missing in your graph, please provide the list of node names (or IDs) from your knowledge graph that correspond to KEGG pathways. For example, this might include:

  • KEGG identifiers like hsa04110
  • Pathway names like “Cell cycle” or “Glycolysis / Gluconeogenesis”—ideally matching exact KEGG naming

With those node names in hand, I can:

  1. Match them against the official KEGG list.
  2. Generate two clear lists:
    • Present in your graph
    • Missing from your graph (i.e., not represented)

If you can share your node set (even a sample if too large), we can proceed immediately. Let me know when you’re ready!

Sources

You said:

based on my knowledge graph I uploaded, is there any relation between lung cancer and the immune system?

ChatGPT said:

In the knowledge graph you uploaded, there aren’t any nodes explicitly labeled with immune-related terms (like “immune,” “T cell,” “macrophage,” “cytokine,” etc.) that directly link to lung cancer concepts.

That means your graph doesn’t appear to contain an obvious connection between lung cancer and the immune system—at least not through explicitly named immune processes or cell types.

If you want, I can run a broader search for indirect immune-related concepts (e.g., inflammation, checkpoint pathways like PD-1/PD-L1, MHC) to see if they’re present but labeled differently.

You said:

Based on my knowledge graph I uploaded is there any relation between lung cancer and inflammation or genes related to inflammation?

ChatGPT said:

Your uploaded knowledge graph doesn’t contain any nodes that explicitly mention inflammation or common inflammation-related genes (e.g., TNF, interleukins, NF-κB, COX-2, JAK/STAT, chemokines).

So based on the current data, there’s no recorded link between lung cancer and inflammation in your network—either directly or via inflammation-related genes.

If you want, I can try mapping your existing nodes to KEGG’s inflammation and immune-related pathways to catch indirect associations that aren’t obvious from node names alone.

You said:

Are there any nodes in my graph that maps to KEGG inflammation and immune-related pathways?

ChatGPT said:

Here’s what I discovered regarding KEGG immune- and inflammation-related pathways, and how they relate (or don’t) to the nodes in your uploaded knowledge graph:

  1. Key KEGG Immune-Related Pathways

KEGG organizes numerous human pathways under the “Immune System” category, including:

  • Toll-like receptor signaling (hsa:04620)
  • NOD-like receptor signaling (hsa:04621)
  • RIG-I-like receptor signaling (hsa:04622)
  • Chemokine signaling (hsa:04062)
  • T cell receptor signaling
  • B cell receptor signaling
  • Antigen processing & presentation
  • Th1/Th2/Th17 cell differentiation
  • IL-17 signaling
  • Natural killer cell mediated cytotoxicity
  • Complement & coagulation cascades
  • Hematopoietic cell lineage
  • Leukocyte transendothelial migration
  • Intestinal immune network for IgA production KEGG+2KEGG+2KEGG
  1. Does Your Graph Map to These KEGG Pathways?

From your graph’s node name entries, I didn’t see any nodes that correspond to the KEGG immune or inflammation pathways listed above. There are no direct matches like:

  • “Toll-like receptor signaling”
  • “Chemokine signaling”
  • “Antigen processing and presentation”
  • “Th1 cell differentiation,” etc.

So, based solely on node names, none of the canonical KEGG immune or inflammation pathways appear to be represented in your graph.

  1. Next Steps to Explore Potential Indirect Links

Even if those pathways aren’t explicitly named, your graph might still include immune- or inflammation-related genes under alternate labels. If you’d like, I can help:

  • Search for common immune-related genes in your graph (e.g., TLR4, NLRP3, interleukins, NF-κB) to spot indirect associations;
  • Perform pathway mapping, using tools like KEGG Mapper or Reactome, to see if the gene set from your graph corresponds to any immune-related pathways—even if they’re not explicitly named.

Would you like me to proceed with one of those approaches to dig deeper?

Sources

You said:

Search for common immune-related genes in my graph and pathways using KEGG Mapper

ChatGPT said:

Your uploaded knowledge graph doesn’t contain any nodes that match common immune-related genes from the KEGG immune and inflammation pathways list—at least not under standard gene symbols like IL6, TNF, TLR4, STAT3, etc.

This means KEGG Mapper wouldn’t find direct immune pathway hits from your current node set unless those genes are present under alternate labels or embedded inside other entity names.

If you want, I can:

  • Expand the search to look for partial matches (e.g., “IL-6” or “interleukin 6” instead of strictly “IL6”)
  • Try mapping all your nodes to KEGG to see if indirect immune pathway associations appear

You said:

Based on the above analysis and my knowledge graph would you say investigating the role of the immune system in lung cancer would uncover interesting therapeutic targets?

ChatGPT said:

Thought for 9s

Short answer: Yes — very likely.
Even though your uploaded graph does not currently show immune or inflammation nodes, independent evidence strongly supports that the immune system and inflammatory programs are central to lung-cancer biology and have already yielded major therapeutic targets (and will likely yield more). PMC+1

Why I say that (big points, with sources):

  • Immune checkpoint therapy (anti-PD-1/PD-L1, anti-CTLA-4) is an established, practice-changing class of treatments in non-small cell lung cancer (NSCLC) — i.e., the immune axis is clinically actionable in lung cancer. PMCAACR Journals
  • The tumor immune microenvironment (TIME) — infiltrating T cells, myeloid cells, cytokines and stromal factors — strongly influences lung cancer progression and patient outcome, and is a major focus for biomarker/target discovery. PMC+1
  • Chronic inflammation (IL-1, IL-6, TNF, NF-κB, STAT3 and related signaling) promotes tumor initiation/progression and shapes the microenvironment in lung cancer; those pathways are plausible therapeutic targets or combinatorial partners with immunotherapy. FrontiersPMC
  • Beyond PD-1/PD-L1, many immune/TME components are under active translational study (co-inhibitory/activating receptors, cytokines, myeloid suppressor cells, TME remodeling) — so there’s real opportunity for new targets or combination strategies. NatureBioMed Central

What this means for your graph / next steps I recommend (practical, doable):

  1. Expand node matching to include gene name variants and immune terms (e.g., IL6, IL-6, interleukin 6, PDCD1, PD-1, CD274, PD-L1, TLR4, NFKB1, STAT3) — you may have immune hits under alternate labels. I can do this mapping for you and return matches.
  2. Map your gene set (all nodes that are genes/keywords) to pathway databases (KEGG, Reactome) and to immune gene lists — that will reveal indirect associations even if pathway names aren’t nodes. I can run KEGG Mapper / Reactome mapping and give a present/missing report.
  3. If you have expression / mutation / clinical metadata, do: (a) differential expression / mutation enrichment for immune genes, (b) deconvolution to estimate immune cell infiltration, (c) network-neighborhood expansion to find immune neighbors — each can point to actionable targets.
  4. Prioritize candidate targets by combining evidence: presence in your graph, pathway membership, druggability, and clinical relevance (e.g., known checkpoint ligands, cytokines, myeloid regulators).

Would you like me to (A) run a relaxed search of your graph for immune/inflammation gene name variants now, and then (B) map any hits to KEGG/Reactome so we can produce a ranked list of immune-related targets and pathways? If yes I’ll start immediately and return the matched nodes + pathway hits.

Sources

 

 

Short answer: Yes — very likely.
Even though your uploaded graph does not currently show immune or inflammation nodes, independent evidence strongly supports that the immune system and inflammatory programs are central to lung-cancer biology and have already yielded major therapeutic targets (and will likely yield more). (PMC)

Why I say that (big points, with sources):

  • Immune checkpoint therapy (anti-PD-1/PD-L1, anti-CTLA-4) is an established, practice-changing class of treatments in non-small cell lung cancer (NSCLC) — i.e., the immune axis is clinically actionable in lung cancer. (PMC, AACR Journals)
  • The tumor immune microenvironment (TIME) — infiltrating T cells, myeloid cells, cytokines and stromal factors — strongly influences lung cancer progression and patient outcome, and is a major focus for biomarker/target discovery. (PMC)
  • Chronic inflammation (IL-1, IL-6, TNF, NF-κB, STAT3 and related signaling) promotes tumor initiation/progression and shapes the microenvironment in lung cancer; those pathways are plausible therapeutic targets or combinatorial partners with immunotherapy. (Frontiers, PMC)
  • Beyond PD-1/PD-L1, many immune/TME components are under active translational study (co-inhibitory/activating receptors, cytokines, myeloid suppressor cells, TME remodeling) — so there’s real opportunity for new targets or combination strategies. (Nature, BioMed Central)

What this means for your graph / next steps I recommend (practical, doable):

  1. Expand node matching to include gene name variants and immune terms (e.g., IL6, IL-6, interleukin 6, PDCD1, PD-1, CD274, PD-L1, TLR4, NFKB1, STAT3) — you may have immune hits under alternate labels. I can do this mapping for you and return matches.
  2. Map your gene set (all nodes that are genes/keywords) to pathway databases (KEGG, Reactome) and to immune gene lists — that will reveal indirect associations even if pathway names aren’t nodes. I can run KEGG Mapper / Reactome mapping and give a present/missing report.
  3. If you have expression / mutation / clinical metadata, do: (a) differential expression / mutation enrichment for immune genes, (b) deconvolution to estimate immune cell infiltration, (c) network-neighborhood expansion to find immune neighbors — each can point to actionable targets.
  4. Prioritize candidate targets by combining evidence: presence in your graph, pathway membership, druggability, and clinical relevance (e.g., known checkpoint ligands, cytokines, myeloid regulators).

Would you like me to (A) run a relaxed search of your graph for immune/inflammation gene name variants now, and then (B) map any hits to KEGG/Reactome so we can produce a ranked list of immune-related targets and pathways? If yes I’ll start immediately and return the matched nodes + pathway hits.

Based on the uploaded knowledge graph would there be any plausible reason to develop PD-L1 inhibitors for treatment of lung cancer?

ChatGPT said:

Thought for a few seconds

Short answer: Not from the uploaded graph alone.
Your current knowledge graph contains no node matching PD-L1 (CD274) or close synonyms (PD-L1, PDL1, PDCD1LG1/2) and—more broadly—no explicit immune/inflammation gene nodes were found. So, based solely on the graph you uploaded there’s no direct evidence in that dataset that would, by itself, justify developing PD-L1 inhibitors.

That said — important context and why the answer is still “probably yes” in real biology:

  • Clinically, PD-1/PD-L1 blockade is already an established, effective therapy in many lung cancers (especially NSCLC). The absence of PD-L1 in your graph likely reflects a gap in the data you uploaded (labels, scope, or data sources), not a biological counterargument.
  • Rationale for PD-L1 targeting typically depends on features that your graph currently lacks: PD-L1 (CD274) expression on tumor or immune cells, presence of PD-1 on T cells, tumor mutational burden/neoantigens, and evidence of T cell infiltration or an immunosuppressive microenvironment. None of those features appear in your nodes.

If you want to pursue PD-L1 as a target for this dataset, here are concrete next steps I recommend (I can do these for you):

  1. Search the graph for PD-L1 synonyms and related immune genes (CD274, PDCD1, PDCD1LG2, PD1, PDL1, PD-L2, CD8A, CTLA4, etc.) — I’ll run a relaxed search (IL-6 vs IL6, hyphens, full names) to catch alternate labels.
  2. Map all gene nodes to standard gene symbols (HGNC) and then run pathway mapping (KEGG/Reactome) to reveal immune pathway hits even if pathway names aren’t nodes.
  3. If you have expression or mutation metadata (linked to nodes), check: PD-L1 expression levels, TMB/neoantigen load, and immune-deconvolution signatures — these are strong predictors of benefit from PD-1/PD-L1 therapies.
  4. Network neighborhood expansion: find genes directly connected to known immune regulators — that can reveal indirect immune associations missed by exact-name matching.
  5. If no immune content is present, consider integrating orthogonal data (TCGA expression for lung cancer, published PD-L1 expression datasets) to augment the graph and inform target prioritization.

Summary and Discussions:  The goal of our original curation was to determine if gaps of knowledge exists between five whole exome studies on mutational spectrum in non small cell lung cancer (NSCLC) and if differences in mutational spectrum in smokers versus non-smokers.  Our manual curation involved a process in which individual genes and mutations were analayzed for literature coverage in Pubmed and if the potential affected pathways were also being investigated in lung cancer research (what we called a literomics approach).  Our manual analysis (as of 2016) revealed while many mutated genes were involved in the well researched fields of Cell Cycle, there were substantial gaps in knowledge of the role of the immune system in lung cancer, especially given the mutational spectrum seen in these studies.  We had also noticed a number of fusion proteins which may be interesting for further (post 2016) investigation.  This involved some inference into the use of ALK inhibitors and a suggestion of noncanonical pathways of EGFR to smoker versus nonsmoker patients, based on differences in mutational spectrum and KEGG analysis.

Using both an AI tool to generate knowledge graphs and gain insights into knowledge gaps (InfraNodus) and a generative AI new tool (Chat GPT5) we attempted to determine if our inital analysis in 2016 using more labor intensive manual curation methods could be similar to results that both AI tools could infer.  It is interesting to note that InfraNodus generated knowledge graphs could generate concepts and relationships pertinent to lung cancer, mutational spectrum and gave some interesting insights into the importance of transversions, especially relating to fusion proteins.  InfraNodus did not see much relations to immune functions however to further probe this we asked the same question to GPT5 in two different formats: with text alone and text with uploaded knowledge graph.   Surprisingly Chat GPT had some issues retrieving data from certain online open access databases such as NCBI GO but better luck with the KEGG database.  However GPT, being trained on the most recent data inferred there must be an immune component of lung cancer, although it admitted this was from recent studies; not the studies we supplied to it.  When we narrowed down GPT to look at studies before 2018 there was similarities in the relations and lack of relations we had found in our previous manual method.  We then supplied GPT with our knowledge graph and forced GPT to focus on our knowledge graph from older studies.  Under these constraints GPT correctly admitted there were no links between the immune system and lung cancer mutational specrum although it did give some interesting insights into the role of fusion proteins and reactive oxygen signaling.  After our intial curation, one of our experts Dr. Larry Bernstein had noticed that KEAP1 and 2 showed genetic alterations in the studies, as he suggested there were differences in redox signaling between smokers and nonsmokers.  KEAP1 and 2 are intracellular redox sensors.

 

Therefore it is possible that GPT alone, including the new 5 version, may not be as effective in complex inference into biomedical literature analysis, and a human expert curated knowledge graph incorporated into GPT analysis returns better inference and more novel insights than either modality alone.

For further reading on Artificial Intelligence, Machine Learning and Immunotherapy on this Open Access Scientific Journal please read these articles:

https://pharmaceuticalintelligence.com/2021/07/06/yet-another-success-story-machine-learning-to-predict-immunotherapy-response/

https://pharmaceuticalintelligence.com/2021/05/04/machine-learning-ml-in-cancer-prognosis-prediction-helps-the-researcher-to-identify-multiple-known-as-well-as-candidate-cancer-diver-genes/

Part D: Curation entitled Multiple Lung Cancer Genomic Projects Suggest New Targets, Research Directions for Non-Small Cell Lung Cancer originally published on 09/05/2014

  • Note the text below this point was used for all AI-based text analsysis

UPDATED 10/10/2021

lung cancer

(photo credit: cancer.gov)

A report Lung Cancer Genome Surveys Find Many Potential Drug Targets, in the NCI Bulletin,

http://www.cancer.gov/ncicancerbulletin/091812/page2

summarizes the clinical importance of five new lung cancer genome sequencing projects. These studies have identified genetic and epigenetic alterations in hundreds of lung tumors, of which some alterations could be taken advantage of using currently approved medications.

The reports, all published this month, included genomic information on more than 400 lung tumors. In addition to confirming genetic alterations previously tied to lung cancer, the studies identified other changes that may play a role in the disease.

Collectively, the studies covered the main forms of the disease—lung adenocarcinomas, squamous cell cancers of the lung, and small cell lung cancers.

“All of these studies say that lung cancers are genomically complex and genomically diverse,” said Dr. Matthew Meyerson of Harvard Medical School and the Dana-Farber Cancer Institute, who co-led several of the studies, including a large-scale analysis of squamous cell lung cancer by The Cancer Genome Atlas (TCGA) Research Network.

Some genes, Dr. Meyerson noted, were inactivated through different mechanisms in different tumors. He cautioned that little is known about alterations in DNA sequences that do not encode genes, which is most of the human genome.

Four of the papers are summarized below, with the first described in detail, as the Nature paper used a multi-‘omics strategy to evaluate expression, mutation, and signaling pathway activation in a large cohort of lung tumors. A literature informatics analysis is given for one of the papers.  Please note that links on GENE names usually refer to the GeneCard entry.

Paper 1. Comprehensive genomic characterization of squamous cell lung cancers[1]

The Cancer Genome Atlas Research Network Project just reported, in the journal Nature, the results of their comprehensive profiling of 230 resected lung adenocarcinomas. The multi-center teams employed analyses of

  • microRNA
  • Whole Exome Sequencing including
    • Exome mutation analysis
    • Gene copy number
    • Splicing alteration
  • Methylation
  • Proteomic analysis

Summary:

Some very interesting overall findings came out of this analysis including:

  • High rates of somatic mutations including activating mutations in common oncogenes
  • Newly described loss of function MGA mutations
  • Sex differences in EGFR and RBM10 mutations
  • driver roles for NF1, MET, ERBB2 and RITI identified in certain tumors
  • differential mutational pattern based on smoking history
  • splicing alterations driven by somatic genomic changes
  • MAPK and PI3K pathway activation identified by proteomics not explained by mutational analysis = UNEXPLAINED MECHANISM of PATHWAY ACTIVATION

however, given the plethora of data, and in light of a similar study results recently released, there appears to be a great need for additional mining of this CGAP dataset. Therefore I attempted to curate some of the findings along with some other recent news relevant to the surprising findings with relation to biomarker analysis.

Makeup of tumor samples

230 lung adenocarcinomas specimens were categorized by:

Subtype

33% acinar

25% solid

14% micro-papillary

9% papillary

8% unclassified

5% lepidic

4% invasive mucinous
Gender

Smoking status

81% of patients reported past of present smoking

The authors note that TCGA samples were combined with previous data for analysis purpose.

A detailed description of Methodology and the location of deposited data are given at the following addresses:

Publication TCGA Web Page: https://tcga-data.nci.nih.gov/docs/publications/luad_2014/

Sequence files: https://cghub.ucsc.edu

Results:

Gender and Smoking Habits Show different mutational patterns

 

WES mutational analysis

  1. a) smoking status

– there was a strong correlations of cytosine to adenine nucleotide transversions with past or present smoking. In fact smoking history separated into transversion high (past and previous smokers) and transversion low (never smokers) groups, corroborating previous results.

mutations in groups              Transversion High                   Transversion Low

TP53, KRAS, STK11,                 EGFR, RB1, PI3CA

     KEAP1, SMARCA4 RBM10

 

  1. b) Gender

Although gender differences in mutational profiles have been reported, the study found minimal number of significantly mutated genes correlated with gender. Notably:

  • EGFR mutations enriched in female cohort
  • RBM10 loss of function mutations enriched in male cohort

Although the study did not analyze the gender differences with smoking patterns, it was noted that RBM10 mutations among males were more prevalent in the transversion high group.

Whole exome Sequencing and copy number analysis reveal Unique, Candidate Driver Genes

Whole exome sequencing revealed that 62% of tumors contained mutations (either point or indel) in known cancer driver genes such as:

KRAS, EGFR, BRMF, ERBB2

However, authors looked at the WES data from the oncogene-negative tumors and found unique mutations not seen in the tumors containing canonical oncogenic mutations.

Unique potential driver mutations were found in

TP53, KEAP1, NF1, and RIT1

The genomics and expression data were backed up by a proteomics analysis of three pathways:

  1. MAPK pathway
  2. mTOR
  3. PI3K pathway

…. showing significant activation of all three pathways HOWEVER the analysis suggested that activation of signaling pathways COULD NOT be deduced from DNA sequencing alone. Phospho-proteomic analysis was required to determine the full extent of pathway modification.

For example, many tumors lacked an obvious mutation which could explain mTOR or MAPK activation.

 

Altered cell signaling pathways included:

  • Increased MAPK signaling due to activating KRAS
  • Higher mTOR due to inactivating STK11 leading to increased proliferation, translation

Pathway analysis of mutations revealed alterations in multiple cellular pathways including:

  • Reduced oxidative stress response
  • Nucleosome remodeling
  • RNA splicing
  • Cell cycle progression
  • Histone methylation

Summary:

Authors noted some interesting conclusions including:

  1. MET and ERBB2 amplification and mutations in NF1 and RIT1 may be unique driver events in lung adenocarcinoma
  2. Possible new drug development could be targeted to the RTK/RAS/RAF pathway
  3. MYC pathway as another important target
  4. Cluster analysis using multimodal omics approach identifies tumors based on single-gene driver events while other tumor have multiple driver mutational events (TUMOR HETEROGENEITY)

Paper 2. A Genomics-Based Classification of Human Lung Tumors[2]

The paper can be found at

http://stm.sciencemag.org/content/5/209/209ra153

by The Clinical Lung Cancer Genome Project (CLCGP) and Network Genomic Medicine (NGM),*,

Paper Summary

This sequencing project revealed discrepancies between histologic and genomic classification of lung tumors.

Methodology

– mutational analysis by whole exome sequencing of 1255 lung tumors of histologically

defined subtypes

– immunohistochemistry performed to verify reclassification of subtypes based on sequencing data

Results

  • 55% of all cases had at least one oncogenic alteration amenable to current personalized treatment approaches
  • Marked differences existed between cluster analysis within and between preclassified histo-subtypes
  • Reassignment based on genomic data eliminated large cell carcinomas
  • Prospective classification of 5145 lung cancers allowed for genomic classification in 75% of patients
  • Identification of EGFR and ALK mutations led to improved outcomes

Conclusions:

It is feasible to successfully classify and diagnose lung tumors based on whole exome sequencing data.

Paper 3. Genomic Landscape of Non-Small Cell Lung Cancer in Smokers and Never-Smokers[3]

A link to the paper can be found here with Graphic Summary: http://www.cell.com/cell/abstract/S0092-8674%2812%2901022-7?cc=y?cc=y

Methodology

  • Whole genome sequencing and transcriptome sequencing of cancerous and adjacent normal tissues from 17 patients with NSCLC
  • Integrated RNASeq with WES for analysis of
    • Variant analysis
    • Clonality by variant allele frequency anlaysis
    • Fusion genes
  • Bioinformatic analysis

Results

  • 3,726 point mutations and more than 90 indels in the coding sequence
  • Smokers with lung cancer show 10× the number of point mutations than never-smokers
  • Novel lung cancer genes, including DACH1, CFTR, RELN, ABCB5, and HGF were identified
  • Tumor samples from males showed high frequency of MYCBP2 MYCBP2 involved in transcriptional regulation of MYC.
  • Variant allele frequency analysis revealed 10/17 tumors were at least biclonal while 7/17 tumors were monoclonal revealing majority of tumors displayed tumor heterogeneity
  • Novel pathway alterations in lung cancer include cell-cycle and JAK-STAT pathways
  • 14 fusion proteins found, including ROS1-ALK fusion. ROS1-ALK fusions have been frequently found in lung cancer and is indicative of poor prognosis[4].
  • Novel metabolic enzyme fusions
  • Alterations were identified in 54 genes for which targeted drugs are available.           Drug-gable mutant targets include: AURKC, BRAF, HGF, EGFR, ERBB4, FGFR1, MET, JAK2, JAK3, HDAC2, HDAC6, HDAC9, BIRC6, ITGB1, ITGB3, MMP2, PRKCB, PIK3CG, TERT, KRAS, MMP14

Table. Validated Gene-Fusions Obtained from Ref-Seq Data

Note: Gene columns contain links for GeneCard while Gene function links are to the    gene’s GO (Gene Ontology) function.

GeneA (5′) GeneB (3′) GeneA function (link to Gene Ontology) GeneB function (link to Gene Ontology) known function (refs)
GRIP1 TNIP1 glutamate receptor IP transcriptional repressor
SGMS1 STK10 sphingolipid synthesis ser/thr kinase
RASSF3 TTYH2 GTP-binding protein chloride anion channel
KDELR2 ROS1, GOPC ER retention seq. binding proto-oncogenic tyr kinase
ACSL4 DCAF6 fatty acid synthesis ?
MARCH8 PRKG1 ubiquitin ligase cGMP dependent protein kinase
APAF1 UNC13B, TLN1 caspase activation cytoskeletal
EML4 ALK microtubule protein tyrosine kinase
EDR3,PHC3 LOC441601 polycomb pr/DNA binding ?
DKFZp761L1918,RHPN2 ANKRD27 Rhophilin (GTP binding pr ankyrin like
VANGL1 HAO2 tetraspanin family oxidase
CACNA2D3 FLNB VOC Ca++ channel filamin (actin binding)

Author’s Note:

There has been a recent literature on the importance of the EML4-ALK fusion protein in lung cancer. EML4-ALK positive lung tumors were found to be les chemo sensitive to cytotoxic therapy[5] and these tumor cells may exhibit an epitope rendering these tumors amenable to immunotherapy[6]. In addition, inhibition of the PI3K pathway has sensitized EMl4-ALK fusion positive tumors to ALK-targeted therapy[7]. EML4-ALK fusion positive tumors show dependence on the HSP90 chaperone, suggesting this cohort of patients might benefit from the new HSP90 inhibitors recently being developed[8].

Table. Significantly mutated genes (point mutations, insertions/deletions) with associated function.

Gene Function
TP53 tumor suppressor
KRAS oncogene
ZFHX4 zinc finger DNA binding
DACH1 transcription factor
EGFR epidermal growth factor receptor
EPHA3 receptor tyrosine kinase
ENSG00000205044
RELN cell matrix protein
ABCB5 ABC Drug Transporter

Table. Literature Analysis of pathways containing significantly altered genes in NSCLC reveal putative targets and risk factors, linkage between other tumor types, and research areas for further investigation.

Note: Significantly mutated genes, obtained from WES, were subjected to pathway analysis (KEGG Pathway Analysis) in order to see which pathways contained signicantly altered gene networks. This pathway term was then used for PubMed literature search together with terms “lung cancer”, “gene”, and “NOT review” to determine frequency of literature coverage for each pathway in lung cancer. Links are to the PubMEd search results.

KEGG pathway Name # of PUBMed entries containing Pathway Name, Gene ANDLung Cancer
Cell cycle 1237
Cell adhesion molecules (CAMs) 372
Glioma 294
Melanoma 219
Colorectal cancer 207
Calcium signaling pathway 175
Prostate cancer 166
MAPK signaling pathway 162
Pancreatic cancer 88
Bladder cancer 74
Renal cell carcinoma 68
Focal adhesion 63
Regulation of actin cytoskeleton 34
Thyroid cancer 32
Salivary secretion 19
Jak-STAT signaling pathway 16
Natural killer cell mediated cytotoxicity 11
Gap junction 11
Endometrial cancer 11
Long-term depression 9
Axon guidance 8
Cytokine-cytokine receptor interaction 8
Chronic myeloid leukemia 7
ErbB signaling pathway 7
Arginine and proline metabolism 6
Maturity onset diabetes of the young 6
Neuroactive ligand-receptor interaction 4
Aldosterone-regulated sodium reabsorption 2
Systemic lupus erythematosus 2
Olfactory transduction 1
Huntington’s disease 1
Chemokine signaling pathway 1
Cardiac muscle contraction 1
Amyotrophic lateral sclerosis (ALS) 1

A few interesting genetic risk factors and possible additional targets for NSCLC were deduced from analysis of the above table of literature including HIF1-α, mIR-31, UBQLN1, ACE, mIR-193a, SRSF1. In addition, glioma, melanoma, colorectal, and prostate and lung cancer share many validated mutations, and possibly similar tumor driver mutations.

KEGGinliteroanalysislungcancer

 please click on graph for larger view

Paper 4. Mapping the Hallmarks of Lung Adenocarcinoma with Massively Parallel Sequencing[9]

For full paper and graphical summary please follow the link: http://www.cell.com/cell/abstract/S0092-8674%2812%2901061-6

Highlights

  • Exome and genome characterization of somatic alterations in 183 lung adenocarcinomas
  • 12 somatic mutations/megabase
  • U2AF1, RBM10, and ARID1A are among newly identified recurrently mutated genes
  • Structural variants include activating in-frame fusion of EGFR
  • Epigenetic and RNA deregulation proposed as a potential lung adenocarcinoma hallmark

Summary

Lung adenocarcinoma, the most common subtype of non-small cell lung cancer, is responsible for more than 500,000 deaths per year worldwide. Here, we report exome and genome sequences of 183 lung adenocarcinoma tumor/normal DNA pairs. These analyses revealed a mean exonic somatic mutation rate of 12.0 events/megabase and identified the majority of genes previously reported as significantly mutated in lung adenocarcinoma. In addition, we identified statistically recurrent somatic mutations in the splicing factor gene U2AF1 and truncating mutations affecting RBM10 and ARID1A. Analysis of nucleotide context-specific mutation signatures grouped the sample set into distinct clusters that correlated with smoking history and alterations of reported lung adenocarcinoma genes. Whole-genome sequence analysis revealed frequent structural rearrangements, including in-frame exonic alterations within EGFR and SIK2 kinases. The candidate genes identified in this study are attractive targets for biological characterization and therapeutic targeting of lung adenocarcinoma.

Paper 5. Integrative genome analyses identify key somatic driver mutations of small-cell lung cancer[10]

Highlights

  • Whole exome and transcriptome (RNASeq) sequencing 29 small-cell lung carcinomas
  • High mutation rate 7.4 protein-changing mutations/million base pairs
  • Inactivating mutations in TP53 and RB1
  • Functional mutations in CREBBP, EP300, MLL, PTEN, SLIT2, EPHA7, FGFR1 (determined by literature and database mining)
  • The mutational spectrum seen in human data also present in a Tp53-/- Rb1-/- mouse lung tumor model

 

Curator Graphical Summary of Interesting Findings From the Above Studies

DGRAPHICSUMMARYNSLCSEQPOST

The above figure (please click on figure) represents themes and findings resulting from the aforementioned studies including

questions which will be addressed in Future Posts on this site.

UPDATED 10/10/2021

The following article uses RNASeq to screen lung adenocarcinomas for fusion proteins in patients with either low or high tumor mutational burden. Findings included presence of MET fusion proteins in addition to other fusion proteins irrespective if tumors were driver negative by DNASeq screening.

High Yield of RNA Sequencing for Targetable Kinase Fusions in Lung Adenocarcinomas with No Mitogenic Driver Alteration Detected by DNA Sequencing and Low Tumor Mutation Burden

Source:

High Yield of RNA Sequencing for Targetable Kinase Fusions in Lung Adenocarcinomas with No Mitogenic Driver Alteration Detected by DNA Sequencing and Low Tumor Mutation Burden
Ryma BenayedMichael OffinKerry MullaneyPurvil SukhadiaKelly RiosPatrice DesmeulesRyan PtashkinHelen WonJason ChangDarragh HalpennyAlison M. SchramCharles M. RudinDavid M. HymanMaria E. ArcilaMichael F. BergerAhmet ZehirMark G. KrisAlexander Drilon and Marc Ladanyi

Abstract

Purpose: Targeted next-generation sequencing of DNA has become more widely used in the management of patients with lung adenocarcinoma; however, no clear mitogenic driver alteration is found in some cases. We evaluated the incremental benefit of targeted RNA sequencing (RNAseq) in the identification of gene fusions and MET exon 14 (METex14) alterations in DNA sequencing (DNAseq) driver–negative lung cancers.

Experimental Design: Lung cancers driver negative by MSK-IMPACT underwent further analysis using a custom RNAseq panel (MSK-Fusion). Tumor mutation burden (TMB) was assessed as a potential prioritization criterion for targeted RNAseq.

Results: As part of prospective clinical genomic testing, we profiled 2,522 lung adenocarcinomas using MSK-IMPACT, which identified 195 (7.7%) fusions and 119 (4.7%) METex14 alterations. Among 275 driver-negative cases with available tissue, 254 (92%) had sufficient material for RNAseq. A previously undetected alteration was identified in 14% (36/254) of cases, 33 of which were actionable (27 in-frame fusions, 6 METex14). Of these 33 patients, 10 then received matched targeted therapy, which achieved clinical benefit in 8 (80%). In the 32% (81/254) of DNAseq driver–negative cases with low TMB [0–5 mutations/Megabase (mut/Mb)], 25 (31%) were positive for previously undetected gene fusions on RNAseq, whereas, in 151 cases with TMB >5 mut/Mb, only 7% were positive for fusions (P < 0.0001).

Conclusions: Targeted RNAseq assays should be used in all cases that appear driver negative by DNAseq assays to ensure comprehensive detection of actionable gene rearrangements. Furthermore, we observed a significant enrichment for fusions in DNAseq driver–negative samples with low TMB, supporting the prioritization of such cases for additional RNAseq.

Translational Relevance

Inhibitors targeting kinase fusions have shown dramatic and durable responses in lung cancer patients, making their comprehensive detection critical. Here, we evaluated the incremental benefit of targeted RNA sequencing (RNAseq) in the identification of gene fusions in patients where no clear mitogenic driver alteration is found by DNA sequencing (DNAseq)–based panel testing. We found actionable alterations (kinase fusions or MET exon 14 skipping) in 13% of cases apparently driver negative by previous DNAseq testing. Among the driver-negative samples tested by RNAseq, those with low tumor mutation burden (TMB) were significantly enriched for gene fusions when compared with the ones with higher TMB. In a clinical setting, such patients should be prioritized for RNAseq. Thus, a rational, algorithmic approach to the use of targeted RNA-based next-generation sequencing (NGS) to complement large panel DNA-based NGS testing can be highly effective in comprehensively uncovering targetable gene fusions or oncogenic isoforms not just in lung cancer but also more generally across different tumor types.

A Commentary is in the same issue at https://clincancerres.aacrjournals.org/content/25/15/4586?iss=15

Wake Up and Smell the Fusions: Single-Modality Molecular Testing Misses Drivers

by Kurtis D. Davies and Dara L. Aisner

Abstract

Multitarget assays have become common in clinical molecular diagnostic laboratories. However, all assays, no matter how well designed, have inherent gaps due to technical and biological limitations. In some clinical cases, testing by multiple methodologies is needed to address these gaps and ensure the most accurate molecular diagnoses.

See related article by Benayed et al., p. 4712

In this issue of Clinical Cancer Research, Benayed and colleagues illustrate the growing need to consider multiple molecular testing methodologies for certain clinical specimens (1). The rapidly expanding list of actionable molecular alterations across cancer types has resulted in the wide adoption of multitarget testing approaches, particularly those based on next-generation sequencing (NGS). NGS-based assays are commonly viewed as “one-stop shops” to detect a vast array of molecular variants. However, as Benayed and colleagues discuss, even well-designed and highly vetted NGS assays have inherent gaps that, under certain circumstances, are ideally addressed by analyzing the sample using an alternative approach.

In the article, the authors examined a cohort of lung adenocarcinoma patient samples that had been deemed “driver- negative” via MSK-IMPACT, an FDA-cleared test that is widely considered by experts in the field to be one of the best examples of a DNA-based large gene panel NGS assay (2). Of 589 driver-negative cases, 254 had additional material amenable for a different approach: RNA-based NGS designed specifically for gene fusion and oncogenic gene isoform detection. After accounting for quality control failures, 232 samples were successfully sequenced, and, among these, 36 samples (representing an astonishing 15.5% of tested cases) were found to be positive for a driver gene fusion or oncogenic isoform that had not been detected by DNA-based NGS. The real-world value derived from this orthogonal testing schema was more than theoretical, with 8 of 10 (80%) patients demonstrating clinical benefit when treated according to the alteration identified via the RNA-based approach.

To detect gene rearrangements that lead to oncogenic gene fusions (and to detect mutations and insertions/deletions that lead to MET exon 14 skipping), MSK-IMPACT employs hybrid capture-based enrichment of selected intronic regions from genomic DNA. While this approach has proven to be successful in a variety of settings, there are associated limitations that were determined in this study to underlie the discrepancies between MSK-IMPACT and the RNA-based assay. First, some introns that are involved in clinically actionable rearrangement events are very large, thus requiring substantial sequencing capital that can represent a disproportionate fraction of the assay. Despite the ability via NGS to perform sequencing at a large scale, this sequencing capacity is still finite, and thus decisions must be made to sacrifice coverage of certain large genomic regions to ensure sufficient sequencing depth for other desired genomic targets. In the case of MSK-IMPACT (and most other DNA-based NGS assays), certain important introns in NTRK3 and NRG1 are not included in covered content, simply because they are too large (>90 Kb each). The second primary problem with DNA-based analysis of introns is that they often contain highly repetitive elements that are extremely difficult to assess via NGS due to their recurring presence across the genome. Attempts to sequence these regions are largely unfruitful because any sequencing data obtained cannot be specifically aligned/mapped to the desired targeted region of the genome (3). This is particularly true for intron 31 of ROS1, because it contains two repetitive long interspersed nuclear elements, and many DNA-based assays, including MSK-IMPACT, poorly cover this intron (4). In this study by Benayed and colleagues, the most common discrepant alteration was fusion involving ROS1, which accounted for 10 of 36 (28%) cases. At least six of these, those that demonstrated fusion to ROS1 exon 32, were likely directly explained by incomplete intron 31 sequencing. RNA-based analysis is able to overcome the above described limitations owing to the simple fact that sequencing is focused on exons post-splicing and the need to sequence introns is entirely avoided (Fig. 1).

Figure 1.

Schematic representation of underlying genomic complexities that can lead to false-negative gene fusion results in DNA-based NGS analysis. In some cases, RNA-based approaches may overcome the limitations of DNA-based testing.

Lack of sufficient intronic coverage could not account for all of the discrepancies between DNA-based and RNA-based analysis however. Six samples in the cohort were found to be positive for MET exon 14 skipping based on RNA. In five of these, genomic alterations in MET introns 13 or 14 were observed, however they did not conform to canonical splice site alterations and thus were not initially called (although this was addressed by bioinformatics updates). In RNA-based testing, however, determination of exon skipping is simplified such that, regardless of the specific genomic alteration that interferes with splicing, absence of the exon in the transcript is directly observed (5). In another two of the discrepant cases, tumor purity was observed to be low in the sample, meaning that the expected variant allele frequency (VAF) for a genomic event would also likely be low, potentially below detectable levels. However, overexpression of the fusions at the transcript level was theorized to compensate for low VAF (Fig. 1). Additional explanations for discordant findings between the assays included sample-specific poor sequencing in selected introns and complex rearrangements that hindered proper capture (Fig. 1).

The take home message from Benayed and colleagues is simply this: there is no perfect assay that will detect 100% of the potential actionable alterations in patient samples. Even an extremely well designed, thoroughly vetted, and FDA-cleared assay such as MSK-IMPACT will have inherent and unavoidable “holes” due to intrinsic limitations. The solution to this dilemma, as adeptly described by Benayed and colleagues, is additional testing using a different approach. While in an ideal world every clinical tumor sample would be tested by multiple modalities to ensure the most comprehensive clinical assessment, the reality is that these samples are often scant and testing is fiscally burdensome (and often not reimbursed). Therefore, algorithms to determine which samples should be reflexed to secondary assays after testing with a primary assay are critical for maximizing benefit. In this study, the first algorithmic step was lack of an identified driver (because activated oncogenic drivers tend to exist exclusively of each other), which amounted to 23% of samples tested with the primary assay. In addition, the authors found a significantly higher rate of actionable gene fusions in samples with a low (<5 mut/Mb) tumor mutational burden, meaning that this metric, which was derived from the primary assay, could also be used to help inform decision making regarding additional testing. While this scenario is somewhat specific to lung cancer, similar approaches could be prescribed on a cancer type–specific basis.

These findings should be considered a “wake-up call” for oncologists in regard to the ordering and interpretation of molecular testing. It is clear from these and other published findings that advanced molecular analysis has limitations that require nuanced technical understanding. As this arena evolves, it is critical for oncologists (and trainees) to gain an increased comprehension of how to identify when the “gaps” in a test might be most clinically relevant. This requires a level of technical cognizance that has been previously unexpected of clinical practitioners, yet is underscored by the reality that opportunities for effective targeted therapy can and will be missed if the treating oncologist is unaware of how to best identify patients for whom additional testing is warranted. This study also highlights the mantra of “no test is perfect” regardless of prestige of the testing institution, number of past tests performed, or regulatory status. NGS, despite its benefits, does not mean all-encompassing. It is only through the adaptability of laboratories to utilize knowledge such as is provided by Benayed and colleagues that advances in laboratory medicine can be quickly deployed to maximize benefits for oncology patients.

References:

  1. Comprehensive genomic characterization of squamous cell lung cancers. Nature 2012, 489(7417):519-525.
  2. A genomics-based classification of human lung tumors. Science translational medicine 2013, 5(209):209ra153.
  3. Govindan R, Ding L, Griffith M, Subramanian J, Dees ND, Kanchi KL, Maher CA, Fulton R, Fulton L, Wallis J et al: Genomic landscape of non-small cell lung cancer in smokers and never-smokers. Cell 2012, 150(6):1121-1134.
  4. Takeuchi K, Soda M, Togashi Y, Suzuki R, Sakata S, Hatano S, Asaka R, Hamanaka W, Ninomiya H, Uehara H et al: RET, ROS1 and ALK fusions in lung cancer. Nature medicine 2012, 18(3):378-381.
  5. Morodomi Y, Takenoyama M, Inamasu E, Toyozawa R, Kojo M, Toyokawa G, Shiraishi Y, Takenaka T, Hirai F, Yamaguchi M et al: Non-small cell lung cancer patients with EML4-ALK fusion gene are insensitive to cytotoxic chemotherapy. Anticancer research 2014, 34(7):3825-3830.
  6. Yoshimura M, Tada Y, Ofuzi K, Yamamoto M, Nakatsura T: Identification of a novel HLA-A 02:01-restricted cytotoxic T lymphocyte epitope derived from the EML4-ALK fusion gene. Oncology reports 2014, 32(1):33-39.
  7. Yang L, Li G, Zhao L, Pan F, Qiang J, Han S: Blocking the PI3K pathway enhances the efficacy of ALK-targeted therapy in EML4-ALK-positive nonsmall-cell lung cancer. Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine 2014.
  8. Workman P, van Montfort R: EML4-ALK fusions: propelling cancer but creating exploitable chaperone dependence. Cancer discovery 2014, 4(6):642-645.
  9. Imielinski M, Berger AH, Hammerman PS, Hernandez B, Pugh TJ, Hodis E, Cho J, Suh J, Capelletti M, Sivachenko A et al: Mapping the hallmarks of lung adenocarcinoma with massively parallel sequencing. Cell 2012, 150(6):1107-1120.
  10. Peifer M, Fernandez-Cuesta L, Sos ML, George J, Seidel D, Kasper LH, Plenker D, Leenders F, Sun R, Zander T et al: Integrative genome analyses identify key somatic driver mutations of small-cell lung cancer. Nature genetics 2012, 44(10):1104-1110.

Other posts on this site which refer to Lung Cancer and Cancer Genome Sequencing include:

Multi-drug, Multi-arm, Biomarker-driven Clinical Trial for patients with Squamous Cell Carcinoma called the Lung Cancer Master Protocol, or Lung-MAP launched by NCI, Foundation Medicine, and Five Pharma Firms

US Personalized Cancer Genome Sequencing Market Outlook 2018 –

Comprehensive Genomic Characterization of Squamous Cell Lung Cancers

International Cancer Genome Consortium Website has 71 Committed Cancer Genome Projects Ongoing

Non-small Cell Lung Cancer drugs – where does the Future lie?

Lung cancer breathalyzer trialed in the UK

Diagnosing Lung Cancer in Exhaled Breath using Gold Nanoparticles

Multi-drug, Multi-arm, Biomarker-driven Clinical Trial for patients with Squamous Cell Carcinoma called the Lung Cancer Master Protocol, or Lung-MAP launched by NCI, Foundation Medicine, and Five Pharma Firms

Read Full Post »

Genomics-Based Classification

Author and Curator: Larry H. Bernstein, MD, FCAP

and

Curator: Aviva Lev-Ari, PhD, RN

 

This article is a recently reported use of genomics to classify lung cancer published in Science Translational Medicine.

A Genomics-Based Classification of Human Lung Tumors

Sci Transl Med 30 Oct 2013;  5(209), p. 209ra153     http://dx.doi.org/10.1126/scitranslmed.3006802
The Clinical Lung Cancer Genome Project (CLCGP) and Network Genomic Medicine (NGM),*,†
 ↵†Corresponding authors. E-mail: roman.thomas@uni-koeln.de (R.T.); reinhard.buettner@uk-koeln.de (R.B.); juergen.wolf@uk-koeln.de (J.W.)
 ↵* Lists of participants and their affiliations appear at the end of the paper.
Abstract
We characterized genome alterations in 1255 clinically annotated lung tumors of all histological subgroups to identify genetically defined and clinically relevant subtypes. More than 55% of all cases had at least one oncogenic genome alteration
  • potentially amenable to specific therapeutic intervention, including
  • several personalized treatment approaches that are already in clinical evaluation.
Marked differences in the pattern of genomic alterations existed between and within histological subtypes, thus
  • challenging the original histomorphological diagnosis.
  • Immunohistochemical studies confirmed many of these reassigned subtypes.
  • The reassignment eliminated almost all cases of large cell carcinomas,

some of which had therapeutically relevant alterations. Prospective testing of our genomics-based diagnostic algorithm in 5145 lung cancer patients enabled

  • a genome-based diagnosis in 3863 (75%) patients,
  • confirmed the feasibility of rational reassignments of large cell lung cancer, and
  • led to improvement in overall survival in patients with EGFR-mutant or ALK-rearranged cancers.
Thus, our findings provide support for broad implementation of genome-based diagnosis of lung cancer.

Read Full Post »

FDA approves EGFR mutation detection test for NSCLC drug, Tarceva

Author/Reporter: Ritu Saxena, Ph.D.

The cobas EGFR Mutation Test, Roche Molecular Diagnostics, identifies mutations in epidermal growth factor receptor (EGFR) exons 18, 19, 20 and 21 of patients. The FDA has approved the companion diagnostic for the cancer drug Tarceva (erlotinib). It would select non-small cell lung cancer (NSCLC) patients for treatment with EGFR inhibitors. This is the first FDA-approved companion diagnostic that detects EGFR gene mutations, which are present in approximately 10-30% of non-small cell lung cancers (NSCLC). The test is being approved with an expanded use for Tarceva as a first-line treatment for patients with NSCLC that has metastasized and who have certain mutations in the EGFR gene.

Lung cancer, the leading cause of cancer death among both men and women leads to death of more people than colon, breast, and prostate cancers combined. The American Cancer Society’s most recent estimates for lung cancer in the United States for 2012 reveal that about 226,160 new cases of lung cancer will be diagnosed (116,470 in men and 109,690 in women), and there will be an estimated 160,340 deaths from lung cancer (87,750 in men and 72,590 among women), accounting for about 28% of all cancer deaths. NSCLC is the most common type of lung cancer and usually grows and spreads more slowly than small cell lung cancer. Activating EGFR mutations occur in 10–30% NSCLC cases, and lead to hyperdependence of tumors on EGFR signaling and increased sensitivity of EGFR to inhibition by erlotinib. Genentech/OSI Pharmaceuticals/Roche/Chugai Pharmaceutical’s erlotinib (Tarceva) is a small molecule quinazoline and directly and reversibly inhibits the EGFR tyrosine kinase.

Tarceva has been indicated for first-line treatment of cancer with EGFR mutations including NSCLC. The approval is Tarceva’s fourth indication and the third use for lung cancer. The FDA approved Tarceva on April 16, 2010, for maintenance treatment of patients with locally advanced or metastatic NSCLC whose disease has not progressed after four cycles of platinum-based first-line chemotherapy. Tarceva was originally approved in November 2004 for the treatment of patients with locally advanced or metastatic NSCLC after failure of at least one prior chemotherapy regimen.

In a recent multicenter, open label, randomized, phase III clinical trial (EURTAC trial; NCT0044625; http://clinicaltrials.gov/ct2/show/NCT00446225 ), Tarceva was investigated in patients with advanced NSCLC with mutations in the tyrosine kinase (TK) domain of the EGFR. The EURTAC trial was initiated in February 2007 and completed in December 2012 and enrolled around 174 patients. Patients were divided into two experimental arms. Patients in arm 1 were administered Tarceva (150 mg/day) while patients in arm 2 underwent chemotherapy as platinum-based doublets. The chemotherapeutic drugs were administered as Cisplatin (75 mg/m2) / Docetaxel (75 mg/m2); Cisplatin (75 mg/m2) / Gemcitabine (1250 mg/m2; day 1 and 8); Docetaxel (75 mg/m2) /carboplatin (AUC=6); Gemcitabine (1000 mg/m2; day 1 and 8) / Carboplatin (AUC=5). Results revealed that Erlotinib is better tolerated in Chinese population (grade 3-4 toxicities 17%) then in European patients (grade 3-4 toxicities 45%). Erlotinib scored significantly better than chemotherapy in terms of progression-free survival (PFS) with 9.7 versus 5.2 months, respectively (HR 0.37, 95% CI 0.25-0.54). Thus, the results of the trial strengthen the rationale for routine baseline tissue-based assessment of EGFR mutations in patients with NSCLC and for treatment of mutation-positive patients with EGFR tyrosine-kinase inhibitors. (Gridelli C and Rossi A, J Thorac Dis. 2012 Apr 1;4(2):219-20; http://www.ncbi.nlm.nih.gov/pubmed/22833832 )

In conclusion, FDA approval of cobas EGFR Mutation Test is a recent example of how genotyping patients in clinical trials could lead to crucial information regarding personalizing the diagnostic and therapeutic approaches.

Reference:

News brief

Clinical lab products http://www.clpmag.com/all-news/24074-fda-approves-first-companion-diagnostic-to-detect-gene-mutation-linked-with-a-type-of-lung-cancer

Clinical trial http://clinicaltrials.gov/ct2/show/NCT00446225

Research articles

Melosky B. EURTAC first line therapy for non small cell lung carcinoma in epidermal growth factor receptor mutation positive patients: A choice between two TKIs. J Thorac Dis. 2012 Apr 1;4(2):221-2; http://www.ncbi.nlm.nih.gov/pubmed/22833833

Gridelli C and Rossi AJ. EURTAC first-line phase III randomized study in advanced non-small cell lung cancer: Erlotinib works also in European population. Thorac Dis. 2012 Apr 1;4(2):219-20; http://www.ncbi.nlm.nih.gov/pubmed/22833832

Related reading

Nguyen KS and Neal JW. First-line treatment of EGFR-mutant non-small-cell lung cancer: the role of erlotinib and other tyrosine kinase inhibitors. Biologics. 2012;6:337-45; http://www.ncbi.nlm.nih.gov/pubmed/23055691

http://pharmaceuticalintelligence.com/2012/11/06/non-small-cell-lung-cancer-drugs-where-does-the-future-lie/ Curator: Ritu Saxena, Ph.D.

http://pharmaceuticalintelligence.com/2013/03/03/personalized-medicine-in-nsclc/ Curator: Larry H. Bernstein, M.D.

http://pharmaceuticalintelligence.com/2012/11/08/lung-cancer-nsclc-drug-administration-and-nanotechnology/ Author: Tilda Barliya, Ph.D.

http://pharmaceuticalintelligence.com/2012/09/18/personalized-rx-decisions-in-nsclc-treatments-symposium-in-thoracic-oncology/ Reporter: Aviva Lev-Ari, Ph.D., R.N.

http://pharmaceuticalintelligence.com/2013/05/15/diagnosis-of-cardiovascular-disease-treatment-and-prevention-current-predicted-cost-of-care-and-the-promise-of-individualized-medicine-using-clinical-decision-support-systems/ Author/Curator: Larry H. Bernstein, M.D.

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Causes and imaging features of false positives and false negatives on 18F-PET/CT in oncologic imaging

Author and Curator: Dror Nir, PhD

Early this year I have posted on: Whole-body imaging as cancer screening tool; answering an unmet clinical need? F-PET/CT was discussed in this post as a leading modality in that respect. Here I report on an article dedicated to the sources for misdiagnosis; i.e. false negatives and false positives when applying this technology:

Causes and imaging features of false positives and false negatives on 18F-PET/CT in oncologic imaging, Niamh M. Long and Clare S. Smith /Insights into Imaging© European Society of Radiology 201010.1007/s13244-010-0062-3

Abstract

Background

18F-FDG is a glucose analogue that is taken up by a wide range of malignancies. 18F-FDG PET-CT is now firmly established as an accurate method for the staging and restaging of various cancers. However, 18F-FDG also accumulates in normal tissue and other non-malignant conditions, and some malignancies do not take up F18-FDG or have a low affinity for the tracer, leading to false-positive and false-negative interpretations.

Methods

PET-CT allows for the correlation of two separate imaging modalities, combining both morphological and metabolic information. We should use the CT to help interpret the PET findings. In this article we will highlight specific false-negative and false-positive findings that one should be aware of when interpreting oncology scans.

Results

We aim to highlight post-treatment conditions that are encountered routinely on restaging scans that can lead to false-positive interpretations. We will emphasise the importance of using the CT component to help recognise these entities to allow improved diagnostic accuracy.

Conclusion

In light of the increased use of PET-CT, it is important that nuclear medicine physicians and radiologists be aware of these conditions and correlate the PET and CT components to avoid misdiagnosis, over staging of disease and unnecessary biopsies.

Introduction

[18F] 2-fluoro-2deoxy-D-glucose (18F-FDG) PET-CT imaging has become firmly established as an excellent clinical tool in the diagnosis, staging and restaging of cancer. 18F-FDG (a glucose analog) is taken up by cells via glucose transporter proteins. The glucose analog then undergoes phosphorylation by hexokinase to FDG-6 phosphate. Unlike glucose, FDG-phosphate does not undergo further metabolism and so becomes trapped in the cell as the cell membrane is impermeable to FDG-6 phosphate following phosphorylation [1].

Malignant tumors have a higher metabolic rate and generally express higher numbers of specific membrane transporter proteins than normal cells. This results in increased uptake of 18F-FDG by tumor cells and forms the basis of FDG-PET imaging [2]. Glucose however acts as a basic energy substrate for many tissues, and so 18F-FDG activity can be seen both physiologically and in benign conditions. In addition, not all tumors take up FDG [35]. The challenge for the interpreting physician is to recognize these entities and avoid the many pitfalls associated with 18F-FDG PET-CT imaging.

In this article we discuss false-positive and false-negative 18F-FDG PET-CT findings, common and atypical physiological sites of FDG uptake, and benign pathological causes of FDG uptake. We will focus on post-treatment conditions that can result in false-positive findings. We will highlight the importance of utilizing the CT component of the study, not only for attenuation correction but also in the interpretation of the study. The CT component of 18F-FDG PET-CT imaging can provide high-resolution anatomical information, which enables more accurate staging and assessment. For the purposes of this article, we refer to the descriptive terms “false-positive” and “false-negative” findings in the context of oncology imaging.

The authors acknowledge that there are recognized causes of FDG uptake that are not related to malignancy; however in this paper we refer to false-positive findings as FDG uptake that is not tumor related.

Patient preparation

Tumor uptake of FDG is reduced in the presence of raised serum glucose as glucose competes with FDG for uptake by the membrane transporter proteins. In order to prevent false-negative results, it is necessary for the patient to fast for at least 4–6 h prior to the procedure [6]. Induction of a euglycamic hypoinsulinaemic state also serves to reduce the uptake of glucose by the myocardium and skeletal muscle. In the fasting state, the decreased availability of glucose results in predominant metabolism of fatty acids by the myocardium. This reduces the intensity of myocardial uptake and prevents masking of metastatic disease within the mediastinum [6].

The radiotracer is administered intravenously (dose dependent on both the count rate capability of the system used and the patient’s weight), and the patient is left resting in a comfortable position during the uptake phase (60–90 min). Patient discomfort and anxiety can result in increased uptake in skeletal muscles of the neck and paravertebral regions. Muscular contraction immediately prior to or following injection can result in increased FDG activity in major muscle groups [6].

Patients are placed in a warm, quiet room with little stimulation, as speech during the uptake phase is associated with increased FDG uptake in the laryngeal muscles [7].

At our institution we perform the CT component with arms up except for head and neck studies where the arms are placed down by the side. This minimizes artifacts on CT. Depending on the type of cancer, oral contrast to label the bowel and intravenous contrast may also be given. The CT is performed with a full dose similar to a diagnostic CT, and lungs are analyzed following reconstruction with a lung algorithm. The PET scan is performed with 3–4 min per bed position; however the time per bed position will vary in different centers depending on both the dose of FDG administered and the specifications of the camera used for image acquisition. It is beyond the scope of this article to provide detailed procedure guidelines for 18F-FDG PET-CT imaging, and for this purpose we refer the reader to a comprehensive paper by Boellaard et al. [8].

Technical causes of false positives

Misregistration artifact

The evaluation of pulmonary nodules provides a unique challenge for combined PET-CT scanning due to differences in breathing patterns between CT and PET acquisition periods. CT imaging of the thorax is classically performed during a breath-hold; however PET images are acquired during tidal breathing, and this can contribute significantly to misregistration of pulmonary nodules on fused PET-CT images. Misregistration is particularly evident at the lung bases, which can lead to difficulty differentiating pulmonary nodules from focal liver lesions (Fig. 1) [9].

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Fig. 1

18F-FDG PET-CT performed in a 65-year-old male with colorectal cancer. On the coronal PET images, a focus of increased FDG uptake is seen at the right lung base (black arrow). Contrast CT does not show any pulmonary nodules but does demonstrate a liver metastasis in the superior aspect of the right lobe of the liver (yellow arrow)

Acquiring CT imaging of the thorax during quiet respiration can help to minimize misregistration artifacts. It is also important to correlate your PET and CT findings by scrolling up and down to make sure that lesions match.

Injected clot

A further diagnostic pitfall in staging of intrathoracic disease can be caused by injected clot. Injection of radioactive clot following blood withdrawal into the syringe at the time of radiotracer administration can result in pulmonary hotspots [10]. The absence of a CT correlate for a pulmonary hotspot should raise the possibility of injected clot; however this is a diagnosis of exclusion, and it is important to carefully evaluate the adjacent slices to ensure the increased radiotracer activity does not relate to misregistration of a pulmonary nodule or hilar lymph node. The area of abnormal radiotracer uptake should also be closely evaluated on subsequent restaging CT to ensure there has been no interval development of an anatomical abnormality in the region of previously diagnosed injected clot (Fig. 2) [11].

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Fig. 2

18F-FDG PET-CT performed in a 28-year-old male with an osteosarcoma of the femur. A focus of increased FDG uptake (yellow arrow) is identified in the left lower lobe with no CT correlate (a). A 3-month follow-up CT thorax again does not demonstrate any pulmonary nodules confirming that the uptake seen originally on the PET-CT was due to injected clot (b)

Injection artifact

Leakage of radiotracer into the subcutaneous tissues at the injection site or tissued injection can result in subcutaneous tracking of FDG along lymphatic channels in the arm. This can result in spurious uptake in axillary nodes distal to the injection site [12]. Careful attention must be paid to the technical aspects of the study to ensure accurate staging. Injection at the side contralateral to the site of disease is advised where feasible to allow differentiation between artifactual and metastatic uptake, particularly in breast cancer patients. The side of injection should also be clearly documented during administration of radiotracer, and this information should be available to the reader in order to ensure pathological FDG uptake is not spuriously attributed to injection artifact (Fig. 3).

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Fig. 3

18F-FDG PET-CT performed in a 56-year-old woman with colorectal cancer. Some low grade FDG uptake is identified in non-enlarged right axillary nodes (yellow arrow) consistent with injection artifact

Imaging of metallic implants

The use of CT for attenuation correction negates the need for traditional transmission attenuation correction, reducing scanning time. There are however technical factors relating to the use of CT imaging for attenuation correction, which lead to artefacts when imaging metal [9]. The presence of metal implants in the body produces streak artifact on CT imaging and degrades image quality. When CT images are used for attenuation correction, the presence of metal results in over attenuation of PET activity in this region and can result in artifactual ‘hot spots.’ Metal prostheses, dental fillings, indwelling ports and breast expanders and sometimes contrast media are common causes of streak artifact secondary to high photon absorption and can cause attenuation correction artifacts [9]. In order to avoid false positives, particularly when imaging metallic implants careful attenuation should be paid to the nonattenuation corrected images, which do not produce this artifact.

Sites of physiological FDG uptake

Physiological uptake in a number of organs is readily recognized and rarely confused with malignancy. These include cerebral tissue, the urinary system, liver and spleen. Approximately 20% of administered activity is renally excreted in the 2 h post-injection resulting in intense radiotracer activity in the renal collecting systems, ureters and bladder [13]. In order to minimize the intensity of renal activity, patients are advised to void prior to imaging. Moderate physiological FDG uptake is noted in the liver, spleen, GI tract and salivary glands. Uptake in the cecum and right colon tends to be higher than in the remainder of the colon due to the presence of glucose-avid lymphocytes [14].

Other sites of physiological FDG activity can be confused with malignancy. Examples include activity within brown fat, adrenal activity, uterus and ovaries.

Brown fat

FDG uptake in hyper-metabolic brown adipose tissue is well recognized as a potential source of false positive in 18F-FDG PET-CT imaging. The incidence of FDG uptake in brown fat has been reported as between 2.5–4% [1516].

Hypermetabolic brown fat is more commonly identified in children than in adults and is more prevalent in females than in males. It occurs more frequently in patients with low body mass index and in cold weather [15].

Glucose accumulation within brown fat is increased by sympathetic stimulation as brown fat is innervated by the sympathetic nervous system. In view of this, administration of oral propranolol is advised by some authors as it has been shown to reduce the uptake of FDG by brown fat [17]. This is not performed at our institution; however, attempts are made to reduce FDG uptake in brown fat by maintaining a warm ambient temperature and providing patients with blankets during the uptake phase.

The typical distribution of brown fat in a bilateral symmetric pattern in the supraclavicular and neck regions is rarely confused with malignancy. In cases where hypermetabolic brown fat is seen to surround lymph nodes, the CT images should be separately evaluated to allow morphological assessment of the lymph nodes. The classical CT features of pathological replacement of lymph nodes should be sought, namely increased short axis diameter, loss of the fatty hilum and loss of the normal concavity of the lymph node. If the morphology of the lymph node is entirely normal, malignancy can be confidently excluded and the increased uptake attributed to brown fat [18].

Atypical brown fat in the mediastinum can be misinterpreted as nodal metastases and has been identified in the paratracheal, paraoesophageal, prevascular regions, along the pericardium and in the interatrial septum. Extramediastinal sites of brown fat uptake include the paravertebral regions, perinephric, perihepatic and subdiaphragmatic regions and in the intraatrial septum [16].

The absence of an anatomical lesion on CT imaging in areas of FDG uptake should raise the possibility of brown fat to the reader. Careful evaluation of the CT images must be performed to confirm the presence of adipose tissue in the anatomical region correlating to the increased FDG activity on 18F-FDG PET before this activity be attributed to brown fat.

An awareness of the possibility of brown fat in atypical locations is vital to avoid overstaging, and correlation with CT imaging increases reader confidence in differentiating brown fat from malignancy (Fig. 4).

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Fig. 4

18F-FDG PET-CT surveillance scan performed in a 36-year-old male with a history of seminoma. Symmetrical uptake is noted in the neck, supraclavicular fossa and paravertebral regions consistent with typical appearance of brown fat activity (black arrow). Brown fat uptake is also seen in the left supradiaphragmatic region and left paraoesophageal region (yellow arrow) (a). 18F-FDG PET-CT performed in a 48-year-old male with a history of colorectal cancer. Increased FDG uptake is noted within brown fat associated with lipomatous hypertrophy of the intra-atrial septum (b)

Uterine and ovarian uptake

In premenopausal women endometrial uptake of FDG varies cyclically and is increased both at ovulation and during the menstrual phase of the cycle with mean SUV values of 3.5–5 [19]. Endometrial uptake in postmenopausal women is abnormal and warrants further investigation; however benign explanations for increased FDG uptake include recent curettage, uterine fibroids and endometrial polyps [19].

Benign ovarian uptake of FDG in premenopausal women can be associated with ovulation. In postmenopausal women, ovarian uptake of FDG should be further investigated (Fig. 5).

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Fig. 5

18F-FDG PET-CT performed in a 42-year-old premenopausal female with breast cancer. She was scanned during menstruation. FDG uptake is noted within metastatic right axillary nodes (black arrow). Increased FDG uptake is also noted within the endometrial canal of the uterus (yellow arrow), which is thickened on CT, consistent with active menstruation (a). 18F-FDG PET-CT performed in the same 42-year-old woman at a different stage in her menstrual cycle showing resolution of the previously identified uterine uptake (yellow arrow) (b)

Adrenal uptake

18F-FDG PET imaging is commonly used for evaluation of adrenal masses in patients with diagnosed malignancies. Similarly incidental adrenal lesions are commonly identified on staging 18F-FDG PET-CT imaging. The positive predictive value of 18F-FDG PET-CT evaluation of adrenal lesions has been reported as high as 95% with a similarly high negative predictive value of 94% [20].

Causes of false-positive adrenal lesions include angiomyolipoma, adrenal hyperplasia and adrenal adenomas (up to 5%) [2124]. FDG activity greater than that of the liver is generally associated with malignancy; however benign lesions have been reported with greater activity than liver [21].

Evaluation of the CT component can provide additional diagnostic information with identification of HU attenuation values of <10 on noncontrast CT for adrenal adenomas or fat-containing myelolipomata [21].

Symmetrical intense FDG activity with no identifiable abnormality on CT is associated with benign physiological FDG uptake (Fig. 6).

f6 f6-b

Fig. 6

18F-FDG PET-CT performed in a 50-year-old woman with inflammatory breast cancer. Diffuse increased FDG uptake is noted within the right breast (yellow arrow) and in a right axillary node (black arrow), consistent with malignancy (a). Increased symmetrical uptake is also noted within both adrenal glands with no abnormal correlate on CT (yellow arrow) (b). Post-chemotherapy PET-CT performed 5 months later demonstrates resolution of the activity within the breast, increased uptake in the bone marrow consistent with post treatment effect (black arrow) and persistent increased uptake in the adrenal glands (yellow arrow), confirming benign physiological activity (c)

Thyroid uptake

Thyroid uptake is incidentally identified on 18F-FDG PET imaging with a frequency of almost 4%, with a diffuse uptake pattern in roughly half of cases and a focal pattern in the remainder [22]. The majority of diffuse uptake represents chronic thyroiditis, multinodular goiter or Graves’ disease, whereas focal uptake is associated with a risk of malignancy that ranges from 30.9–63.6% in published studies [2223]. Focal thyroid uptake requires further investigation with ultrasound and tissue biopsy.

Uptake in the gastrointestinal tract

The pattern of physiological uptake within the GI tract is highly variable. Low-grade linear uptake is likely related to smooth muscle activity and swallowed secretions. More focal increased uptake in the distal esophagus is sometimes seen with Barrett’s esophagus. In view of this, referral for OGD may be reasonable in cases of increased uptake in the distal esophagus [1424].

The typical pattern of FDG uptake in the stomach is of low-grade activity in a J-shaped configuration. Small bowel typically demonstrates mild heterogeneous uptake throughout. Common pitfalls of small bowel evaluation relate to spuriously high uptake in underdistened or overlapping loops of bowel [1425].

Within the colon, FDG uptake is highly variable, however can be quite avid particularly in the cecum, right colon and rectosigmoid regions. Focal areas of FDG activity within the colon that are of greater intensity than background liver uptake should raise the suspicion of a colonic neoplasm (Fig. 7) [2526].

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Fig. 7

18F-FDG PET-CT restaging scan performed in a 65-year-old female with a history of breast cancer. Incidental focal uptake is identified in the ascending colon where some abnormal thickening is seen on the CT component (yellow arrow). Colonoscopy confirmed the presence of a T3 adenocarcinoma

In a review of over 3,000 patients’ focal areas of abnormal FDG uptake within the gastrointestinal tract (GIT) were identified in 3% of cases of staging 18F-FDG PET-CT studies.

Incidental malignant lesions were identified in 19% of these patients with pre-malignant lesions including adenomas in 42% of the patients [27]. In view of this endoscopy referral is recommended in the absence of a clear benign correlate for focal areas of avid uptake on CT imaging.

Treatment-related causes of false-positive uptake

There are a number of conditions that can occur in patients undergoing treatment for cancer. When imaging these patients to assess for response, we often see these treatment-related conditions. It is important to recognize the imaging features to avoid misdiagnosis.

Thymus/thymic hyperplasia

Thymic hyperplasia post-chemotherapy is a well-described phenomenon. It is generally seen in children and young adults at a median of 12 months post chemotherapy [28]. The presence of increased FDG uptake in the anterior mediastinum can be attributed to thymic hyperplasia by identification of a triangular soft tissue density seen retrosternally on CT with a characteristic bilobed anatomical appearance [29]. In the presence of thymic hyperplasia, there is generally preservation of the normal shape of the gland despite an increase in size [30].

Superior mediastinal extension of thymic tissue is an anatomical variant that has been described in children and young adults (Fig. 8).

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Fig. 8

A 3.5-year-old boy with abdominal Burkitt’s lymphoma. Coronal 18F-FDG PET scan obtained 5 months after completion of treatment shows increased activity in the thymus in an inverted V configuration and in superior thymic extension (white arrow). Note physiologic activity within the right neck in the sternocleidomastoid muscle (a). Axial CT image from the same 18F-FDG PET-CT study performed 5 months after treatment shows a nodule (white arrow) anteromedial to the left brachiocephalic vein (b). Axial fusion image shows that the FDG activity in the superior mediastinum corresponds to this enlarged nodule anteromedial to left brachiocephalic vein (white arrow) (c). Axial fusion image shows increased activity in an enlarged thymus consistent with thymic hyperplasia (white arrow; standardized uptake value 3.0) of similar intensity to activity in superior mediastinum (d)

It presents as a soft tissue nodule anteromedial to the left brachiocephalic vein and represents a remnant of thymic tissue along the path of migration in fetal life. In patients with thymic hyperplasia, a superior mediastinal nodule in this location may represent accessory thymic tissue. An awareness of this physiological variant is necessary to prevent misdiagnosis [28].

G-CSF changes

Granulocyte colony-stimulating factor is a glycoprotein hormone that regulates proliferation and differentiation of granulocyte precursors. It is used to accelerate recovery from chemotherapy-related neutropaenia in cancer patients. Intense increased FDG uptake is commonly observed in the bone marrow and spleen following GCSF therapy; however the bone marrow response to GCSF can be differentiated from pathological infiltration by its intense homogeneous nature without focally increased areas of FDG uptake. Increased FDG uptake attributable to GCSF uptake rapidly decreases following completion of therapy and generally resolves within a month (Fig. 9).

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Fig. 9

18F-FDG PET-CT performed in a 46-year-old male post four cycles of chemotherapy for lymphoma and 2 weeks post administration of G-CSF. Note the diffuse homogeneous increased uptake throughout the bone marrow and the increased uptake in the spleen (yellow arrow)

Marked uptake in the bone marrow can also be seen following chemotherapy, reflecting marrow activation [3132].

Radiation pneumonitis

Inflammatory morphological changes in the radiation field post-irradiation of primary or metastatic lung tumor can result in false-positive diagnosis. Radiation pneumonitis typically occurs following high doses of external beam radiotherapy (>40 Gy). In the acute phase (1–8 weeks) radiation pneumonitis is characterized by ground-glass opacities and patchy consolidation. This can commonly lead to a misdiagnosis of infection. Chronic CT appearances of fibrosis and traction bronchiectasis in the radiation field allow correct interpretation of increased FDG uptake as radiation pneumonitis as opposed to disease recurrence [3334]. Other organs are also sensitive to radiation, and persistent uptake due to inflammatory change can persist for up to 1 year. It is important to elicit a history of radiation from the patient and to correlate the increased uptake with the CT findings to avoid missing a disease recurrence (Fig. 10).

f 10

Fig. 10

18F18-FDG PET-CT performed in a 52-year-old male with newly diagnosed esophageal carcinoma. Increased FDG uptake is identified within the esophagus (black arrow) and an upper abdominal lymph node (yellow arrow), consistent with malignancy (a). 18F18-FDG PET-CT performed 6 weeks post-completion of radiotherapy for esophageal carcinoma. Linear increased uptake is identified along the mediastinum in the radiation port (black arrow). This corresponds to areas of ground-glass change on CT (yellow arrow) consistent with acute radiation change (b)

Infection

Bone marrow suppression places chemotherapy patients at increased risk of infection.

Inflammatory cells such as neutrophils and activated macrophages at the site of infection or inflammation actively accumulate FDG [35].

In the post-therapy setting it has been reported that up to 40% of FDG uptake occurs in non-tumor tissue [12]. Infection is one of the most common causes of false-positive 18F-FDG PET-CT findings post-chemotherapy. Chemotherapy patients are susceptible to a wide variety of infections, including upper respiratory chest infections, pneumonia, colitis and cholecystitis. Reactivation of tuberculous infection can occur in immunocompromised patients post,chemotherapy, and correlation with CT imaging can prevent misdiagnosis in suspected cases.

Atypical infections such as cryptococcosis and pneumocystis can also present as false-positives on FDG imaging (Fig. 11) [36].

f 11

Fig. 11

18F-FDG PET-CT performed in a 57-year-old male 2 weeks following chemotherapy for lung cancer. Increased FDG uptake is noted within the cecum (black arrow). On CT there is some thickening of the cecal wall and stranding of the pericecal fat (yellow arrow) consistent with typhilits

Surgery and radiotherapy

There are inherent challenges in the interpretation of 18F-FDG PET-CT imaging in the postoperative patient. Non-tumor-related uptake of FDG is frequently identified in post-operative wound sites, at colostomy sites or at the site of post-radiation inflammatory change. 18F-FDG PET-CT imaging during the early postoperative/post-radiotherapy period may result in overstaging of patients because of non-neoplastic uptake of FDG [12]. Careful evaluation of the CT component in this setting is vital as CT imaging can provide valuable additional information regarding benign inflammatory conditions commonly encountered in the postoperative setting such as abscesses or wound infection. These conditions are often readily apparent on CT, particularly when oral and/or IV contrast CT is administered.

The reader should also bear in mind that avid uptake of FDG at postoperative/post radiotherapy sites may mask malignant FDG uptake in neighboring structures. In order to minimize non-tumoral uptake of FDG, it is advisable to allow at least 6 weeks post-surgery or completion of radiotherapy prior to performing staging 18F-FDG PET-CT [24].

Talc pleurodesis

Talc pleurodesis is a commonly performed procedure for the treatment of persistent pneumothorax or pleural effusion. The fibrotic/inflammatory reaction results in increased FDG uptake on 18F-FDG PET imaging with corresponding high-density areas of pleural thickening on CT. SUV values of between 2–16.3 have been seen years after the procedure [37].

When increased FDG uptake is indentified in the pleural space in a patient with a known history of pleurodesis, correlation with CT is recommended to detect pleural thickening of increased attenuation that suggests talc rather than tumor.

It is extremely important that a comprehensive history with relevant surgical interventions is available to the reader in order to ensure accurate diagnosis and staging (Fig. 12).

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Fig. 12

18F-FDG PET-CT performed in a 69-year-old male with a history of non-Hodgkin’s lymphoma. The patient had a previous talc pleurodesis for a persistent left pleural effusion. Increased FDG activity is identified within the left pleura (black arrow). CT demonstrates a pleural effusion with high density material along the left pleural surface consistent with talc (yellow arrow)

Flare phenomenon

Bone healing is mediated by osteoblasts, and an early increase in osteoblast activity on successful treatment of metastatic disease has been described [38]. “Bone flare” refers to a disproportionate increase in bone lesion activity on isotope bone scan despite evidence of a therapeutic response to treatment in other lesions and has been well described in breast, prostate and lung tumors. ‘Flare phenomenon’ has also been described on 18F-FDG PET-CT in patients with lung and breast cancer who are receiving chemotherapy [39].

Differentiating between increased FDG uptake due to flare response and true disease progression may not be possible in the early post-treatment studies. While it is recognized that bone flare is a rare phenomenon, an increase in baseline skeletal activity and appearance of new bone lesions despite apparent response or stable disease elsewhere should be interpreted with caution to avoid erroneously suggesting progressive disease.

Osteonecrosis

Osteonecrosis or avascular necrosis has been well described as a complication of combination chemotherapy treatment, especially where it includes intermittent high-dose corticosteroids (e.g., lymphoma patients) [40]. Commonly encountered sites include the hip and less frequently the proximal humerus. Occasionally we can see a discrete entity known as jaw osteonecrosis. Patients receiving IV bisphosphonates for the management of bone metastases are at an increased risk of developing this [41]. The development of osteonecrosis in the mandible is frequently preceded by tooth extraction. Radiographic findings that may be visualized on CT include osteosclerosis, dense woven bone, thickened lamina dura and sub-periosteal bone deposition [42]. FDG uptake can be seen in areas of osteonecrosis (Fig. 13).

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Fig. 13

18F-FDG PET-CT performed in a 46-year-old gentleman with a history of non-Hodgkin’s lymphoma. Increased FDG uptake is identified in the right proximal humerus (black arrow). CT of the area demonstrates a corresponding vague area of sclerosis (yellow arrow). Biopsy of the area yielded osteonecrosis with no evidence of metastatic disease

Insufficiency fractures

Pelvic insufficiency fractures have been described following irradiation for gynecological, colorectal, anal and prostate cancer. They commonly occur within 3–12 months post-radiation treatment, and osteoporosis is often a precipitating factor. FDG uptake in insufficiency fractures ranges from mild and diffuse to intense and heterogeneous. The maximum SUV values are variable with reported values of between 2.4–7.2 [43]. Differentiating insufficiency fractures from bone metastases can prove challenging; however they are often bilateral and occur in characteristic locations within the radiation field—sacral ala, pubic rami and iliac bones. Biopsy of insufficiency fractures can lead to irreparable damage and so careful correlation of 18F-FDG PET imaging with the CT component along with radiation history is vital for correct diagnosis. CT allows evaluation of the bone cortex and adjacent soft tissues, which can confirm the diagnosis of a pathological fracture or a metastatic deposit.

Follow-up of suspected insufficiency fractures demonstrates a reduction in FDG uptake over time (Fig. 14) [43].

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Fig. 14

18F-FDG PET-CT performed in a 46-year-old female, 3 years post-chemo-radiation for cervical carcinoma. Low grade FDG uptake is identified in the left acetabulum and right pubic bone (black arrow). CT demonstrates pathological fractures in these areas consistent with insufficiency fractures (yellow arrow)

Sarcoidosis

Sarcoidosis is a chronic multisystem disorder characterized by non-caseating granulomas and derangement of normal tissue architecture [36]. Sarcoidosis has been reported in association with a variety of malignancies either synchronously or post-chemotherapy. Aggregation of inflammatory cells post-chemotherapy is associated with accumulation of FDG, and the intensity of FDG uptake may correlate with disease activity [36].

When suspected disease recurrence presents with signs and symptoms compatible with sarcoidosis (i.e., mediastinal and bihilar lymphadenopathy), this must be excluded by clinical, radiological and pathological correlation to prevent mistreatment (Fig. 15).

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Fig. 15

18F-FDG PET-CT performed in a 67-year-old male for restaging of laryngeal carcinoma. Increased FDG uptake is noted in the left lower neck and left mediastinum (black arrow). CT demonstrates lymphadenopathy in these areas (yellow arrow), some of which are calcified. Biopsy of the left lower neck node confirmed sarcoidosis

FDG-PET negative tumors

There are a number of malignancies that can be FDG-PET negative. Examples include bronchoalveolar carcinoma and carcinoid tumors in the lung, renal cell carcinomas and hepatomas, mucinous tumors of the GIT and colon, and low grade lymphomas [34448]. Careful evaluation of the CT component of the study however will prevent a misdiagnosis (Fig. 16).

f 16

Fig. 16

18F-FDG PET-CT performed in a 52-year-old female with breast cancer and chronic hepatitis. On the CT component a hyper-enhancing mass is identified in segment 4 of the liver (yellow arrow). No increased FDG activity is identified in this area on the PET component. Biopsy of the mass confirmed the diagnosis of a hepatocellular carcinoma

Osteoblastic metastases

Bone metastases are diagnosed in up to 85% of patients with advanced breast cancer, leading to significant morbidity and mortality. Sclerotic bone metastases are commonly associated with breast carcinoma [49].18F-FDG PET imaging is superior to nuclear bone scan in detection of osteolytic breast metastases; however it commonly fails to diagnose osteoblastic or sclerotic metastases [50]. Review of bony windows on CT imaging allows identification of sclerotic metastases and ensures accurate staging of metastatic bone disease (Fig. 17).

f 17

Fig. 17

Staging 18F-FDG PET-CT performed in a 45-year-old female with newly diagnosed breast cancer. CT demonstrates multiple small sclerotic foci in the spine and pelvis (yellow arrow), consistent with bony metastases. These are FDG negative on the PET component of the study

Discussion/conclusion

18F-FDG PET imaging has dramatically changed cancer staging, and findings of restaging studies commonly effect changes in treatment protocols. 18F-FDG however is not tumor specific. As interpreting physicians we need to be aware of these false positives and false negatives. In this review we have outlined atypical physiological sites of FDG uptake along with common causes of FDG uptake in benign pathological conditions, many of which are treatment related. With 18F-FDG PET-CT we have the advantage of two imaging modalities. The PET component gives us functional information and the CT, anatomical data. We have discussed the importance of dual-modality imaging and correlation with CT imaging of the above conditions. Furthermore CT imaging provides important diagnostic information in evaluation of tumors that poorly concentrate FDG. In light of the increased reliance of 18F-FDG PET-CT for cancer staging, it is vital that radiologists and nuclear medicine physicians be aware of pitfalls in 18F-FDG PET-CT imaging and correlate PET and CT components to avoid misdiagnosis, overstaging of disease and unnecessary biopsies.

 

Other research papers related to the use of 18F-PET in management of cancer were published on this Scientific Web site:

State of the art in oncologic imaging of Lymphoma.

State of the art in oncologic imaging of Colorectal cancers.

State of the art in oncologic imaging of Prostate.

State of the art in oncologic imaging of lungs.

State of the art in oncologic imaging of breast.

Whole-body imaging as cancer screening tool; answering an unmet clinical need?

 

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New Ecosystem of Cancer Research: Cross Institutional Team Science

Curator: Aviva Lev-Ari, PhD, RN

This image has an empty alt attribute; its file name is ArticleID-32.png

WordCloud Image Produced by Adam Tubman

SOURCE: Time Magazine, April 1, 2013: How to Cure Cancer by Bill Saporito

Key argument: Now the Cure for Cancer is possible thanks to the following innovations in the Division of Labor of the research process among institution.

1.  New Cancer Dream Teams deliver better results faster, better understand the metabolic changes of pancreatic cells.

Team Leader: Dan Von Hoff – A five phase parallel process of the Cancer Research endeavor: One tumor researched by FIVE Labs in parallel

  • Penn surgeon, Jeffrey Drebin removes tissue from a cancerous pancreas. Tissue is carried to Hospital Lab where it is prepared for analysis and frozen for preservation.
  • a piece will go to Princeton for metabolomic profiling, amino acids, sugar glutamine and up to 300 metabolites.
  • a piece will go to John Hopkins for DNA analysis by sequence analysis
  • a piece will go to Translational Genomics for chromosome analysis
  • a piece will go to Salk Institute for a look at the stellate (star shape. tissue repair function, also plays a role in cancer) cells – gene expression analysis Lab

Joint Lab work: Superior to any research ever known.

2. Drug agents in development for therapy targeting the genetic mutations

  • reactivate the body’s immune system
  • cut off a tumor’s blood or energy supply
  • restart apoptosis

3. New Biomarkers

  • Allows to identify, target and track cancer cells – PI3K mutation One pathway – three women’s Cancers: Ovarian, endometrial, Breast CA.
  • Dream Team led by

– Dr. Gordon Mills of MD Anderson, PI3K pathway investigator

Teams Science include:

– Women’s cancer specialist from MGH

– Dana Farber (Harvard)

– Vanderbilt University

– Columbia University

– BIDMC

– Memorial Sloan Kettering

Dream Teams results are better than Big Pharma: 95% failure rate for new oncology drugs 50% of Phase III trials – don’t cut it to FDA approval.

Dream Teams will launch Trial as soon as geneticists and biochemists match mutation to drug compound.

Big Targets: Pancreas, Breast Cancer, Lung Cancer

Example: Human trial at FIVE institutions (28-person team) with TWO unapproved drugs from TWO companies with one year of discovery

PARP inhibitor from AstraZeneca was combined with PI3K inhibitor from Novartis to combat BRCA1 gene mutation that develops ovarian cancer and triple negative Breast Cancer. Two unapproved drugs are combined. Result was without precedent.

4. Design and built of a smart chip device to trap circulating tumor cells (CTCs) in a blood sample – early identification of metastasis

5. Better chances of Five-year Survival Rates

  • 1975-1977 – 49%
  • 1978-1989 – 56%
  • 2002 – 2008 – 68%

6. More Americans who have a History of Cancer are alive today than in the past

[including Cancer-free and in-treatment]

  • 2004 – 10.8 millions
  • 2008 – 12 millions
  • 2012 – 13.7 millions

7. There are 94 millions ex-smokers in the US – elevated risk for lung Cancer. 175,00 new lung cancers diagnosed every year. MD Anderson is developing a simple blood test for protein marker that could detect lung cancer earlier than it is found, test to be used in combination with diagnostic imaging and risk models

8. Probability of developing some type of Cancer over one’s lifetime:

  • Men – 1 in 2
  • Women – 1 in 3

9. Funding of Dream Team Science by Stand Up to Cancer ( SU2C) Hollywood investment in Cancer Research

10. Cancer Statistics in the US

  • 2013: 580,350 will die of Cancer, NCI figures and 1.7 millions will be diagnosed, numbers will grow as population ages (1.4 millions in 2006)
  • 2013L Leading Types of Cancer: Prostate, Breast, Lung &Bronchus (~250,000 each type), colon (~100,000)
  • Cost of Cancer in 2008: Medical – $77.4 Billion, lost productivity – $124 Billion

11. Research at John Hopkins is focused on studying the the enzymatic on/off switches of gene expression including mutated genes that produce cancer cells.

12. Memorial Sloan Kettering Cancer Center – extensive research on Epigenetics, New epigenetic drugs can shrink tumors. Complete remission is experienced by patients treated with drugs that nudges T Cells.

Cancer is a complexed disease.

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Personalized Medicine: Clinical Aspiration of Microarrays

Reporter, Writer: Stephen J. Williams, Ph.D.

 In this month’s Science, Mike May (at http://www.sciencemag.org/site/products/lst_20130215.xhtml) describes some of the challenges and successes in introducing microarray analysis to the clinical setting.  Traditionally used for investigational research, microarray is now being developed, customized and used for biomarker analysis, prognostic and predictive value, in a disease-specific manner.

Challenges in data interpretation

      In an interview with Seth Crosby, director of the Genome Technology Access Center at Washington University School of Medicine in St. Louis, “the biggest challenge” in moving microarray to the clinical setting is data interpretation.  The current technology makes it possible to evaluate expression of thousands of genes from a patient’s sample however as Crosby describes is assigning clinical relevance to the data.  For example Crosby explains that Washington University had validated a panel of 45 oncology genes by next generation sequencing and are using these genes to develop diagnostic tests to screen patient tumors for the purpose of determining a personalized therapeutic strategy. Seth Crosby noted it took “hundreds of Ph.D. and M.D. hours” to sift through the hundreds of papers to determine which genes were relevant to a specific cancer type. However, he notes, that once we better understand which changes in the patient’s genome are related to a specific disease we will be able to narrow down the list and be able to produce both economical and more disease-relevant microarrays.

Is this aberration pathogenic or not?

     Microarrays are becoming an invaluable tool in cytogenetics, as eluded by Andy Last, executive vice president of the genetic analysis business unit at Affymetrix.  Certain diseases like Down syndrome have well characterized chromosomal alterations like additions or deletions of parts or entire chromosomes.  According to Affymetrix, the most common use of microarrays is for determining copy number variation.  However according to James Clough, vice president of clinical and genomic services at Oxford Gene Technology, given the hundreds of syndromes associated with chromosomal rearrangements, the challenge will be to determine if a small chromosomal aberration has pathologic significance, given that microarray affords much higher diagnostic yield and speed of analysis than traditional microscopic techniques.  To address this challenge, Oxford Gene Technologies, PerkinElmer, Affymetrix, and Agilent all have custom designed microarrays to evaluate disease specific copy number and SNP (single nucleotide polymorphism) microarrays.  For example PerkinElmer designed OncoChip™ to evaluate copy number variation in more than 1.800 cancer genes.  Agilent makes microarrays that evaluates both copy number variation such as its CGH (comparative genomic hybridization) plus SNP microarrays.  Patricia Barco, product manager for cytogenetics at Agilent, notes these arrays can be used in prenatal and postnatal research and cancer, and “can be customized from more than 28 million probes in our library”.

Custom Tools and Software to Handle the Onslaught of Big Data

     There is a need for FDA approved diagnostic tools based on microarrays. Pathwork Diagnostic’s has one such tool (the Pathwork Tissue of Origin test), which uses 2,000 transcript markers and a proprietary computational algorithm to determine from expression analysis, the tissue of origin of a patient’s tumor.  Pathwork also provides a fast, custom turn-around analytical service for pathologists who encounter difficult to interpret samples.  Illumina provides the Infinium HumanCore BeadChip family of microarrays, which can determine genetic variations for purposes of biological tissue banking.  This system uses a set of over 300,000 SNP probes plus 240,000 exome-based markers.

     Tools have also been developed to validate microarray results.  A common validation strategy is the use of quantitative real-time PCR to verify the expression changes seen on the microarray.  Life Technologies developed the TaqMan OpenArray Real Time PCR plates, which have 3,072 wells and can be custom-formatted using their library of eight million validated TaqMan assays.

Making Sense of the Big Data: Bridging the Knowledge Gap using Bioinformatics

          The use of microarray has spurned industries devoted to developing the bioinformatics software to analyze the massive amounts of data and provide clinical significance.  For example companies such as Expression Analysis use their bioinformatics software to provide pathway analysis for microarray data in order to translate the data into the biology.  Using such strategies can also validate the design of microarrays for various diseases.

Foundation Medicine, Inc., a molecular information company, provides cancer genomics test solutions. It offers FoundationOne, an informative genomic profile to identify a patient’s individual molecular alterations and match them with relevant targeted therapies and clinical trials. The company’s product enables physicians to recommend treatment options for patients based on the molecular subtype of their cancer.

The Canadian Bioinformatics Workshops series recently offered a course on using bioinformatic approaches to analyze clinical data generated from microarray approaches (http://bioinformatics.ca/workshops/2012/bioinformatics-cancer-genomics-bicg).   The course objectives are described below:

Course Objectives

Cancer research has rapidly embraced high throughput technologies into its research, using various microarray, tissue array, and next generation sequencing platforms. The result has been a rapid increase in cancer data output and data types. Now more than ever, having the bioinformatic skills and knowledge of available bioinformatic resources specific to cancer is critical. The CBW will host a 5-day workshop covering the key bioinformatics concepts and tools required to analyze cancer genomic data sets. Participants will gain experience in genomic data visualization tools which will be applied throughout the development of the skills required to analyze cancer -omic data for gene expression, genome rearrangement, somatic mutations and copy number variation. The workshop will conclude with analyzing and conducting pathway analysis on the resultant cancer gene list and integration of clinical data.

Successful Examples of Clinical Ventures Integrating Bioinformatics in Cancer Treatment Decision –Making

The University of Pavia, Italy developed a fully integrated oncology bioinformatics workflow as described on their website and at the ESMO 2012 Congress meeting:

http://abstracts.webges.com/viewing/view.php?congress=esmo2012&congress_id=370&publication_id=2530

ESMO

ONCO-I2B2 PROJECT: A BIOINFORMATICS TOOL INTEGRATING –OMICS AND CLINICAL DATA TO SUPPORT TRANSLATIONAL RESEARCH

Abstract:

2530

Congress:

ESMO 2012

Type:

Abstract

Topic:

Translational research

Authors:

A. Zambelli, D. Segagni, V. Tibollo, A. Dagliati, A. Malovini, V. Fotia, S. Manera, R. Bellazzi; Pavia/IT

  • Body

The ONCO-i2b2 project, supported by the University of Pavia and the Fondazione Salvatore Maugeri (FSM), aims at supporting translational research in oncology and exploits the software solutions implemented by the Informatics for Integrating Biology and the Bedside (i2b2) research centre, an initiative funded by the NIH Roadmap National Centres for Biomedical Computing. The ONCO-i2b2 software is designed to integrate the i2b2 infrastructure with the FSM hospital information system and the Bruno Boerci Biobank, in order to provide well-characterized cancer specimens along with an accurate patients clinical data-base. The i2b2 infrastructure provides a web-based access to all the electronic medical records of cancer patients, and allow researchers analyzing the vast amount of biological and clinical information, relying on a user-friendly interface. Data coming from multiple sources are integrated and jointly queried.

In 2011 at AIOM Meeting we reported the preliminary experience of the ONCO-i2b2 project, now we’re able to present the up and running platform and the extended data set. Currently, more than 4400 specimens are stored and more than 600 of breast cancer patients give the consent for the use of specimens in the context of clinical research, in addition, more than 5000 histological reports are stored in order to integrate clinical data.

Within the ONCO-i2b2 project is possible to query and merge data regarding:

• Anonymous patient personal data;

• Diagnosis and therapy ICD9-CM subset from the hospital information system;

• Histological data (tumour SNOMED and TNM codes) and receptor profile testing (Her2, Ki67) from anatomic pathology database;

• Specimen molecular characteristics (DNA, RNA, blood, plasma and cancer tissues) from the Bruno Boerci Biobank management system.

The research infrastructure will be completed by the development of new set of components designed to enhance the ability of an i2b2 hive to utilize data generated by NGS technology, providing a mechanism to apply custom genomic annotations. The translational tool created at FSM is a concrete example regarding how the integration of different information from heterogeneous sources could bring scientific research closer to understand the nature of disease itself and to create novel diagnostics through handy interfaces.

Disclosure

All authors have declared no conflicts of interest.

NCI has under-taken a similar effort under the Recovery Act (the full text of the latest report is taken from their website http://www.cancer.gov/aboutnci/recovery/recoveryfunding/investmentreports/bioinformatics:

Cancer Bioinformatics: Recovery Act Investment Report

November 2009

Public Health Burden of Cancer

Cancer is the second leading cause of death in the United States after heart disease. In 2009, it is estimated that nearly 1.5 million new cases of invasive cancer will be diagnosed in this country and more than 560,000 people will die of the disease.

To learn more, visit:

Cancer Bioinformatics Program Overview

Over the past five years, NCI’s Center for Biomedical Informatics and Information Technology (CBIIT) has led the effort to develop and deploy the cancer Biomedical Informatics Grid® (caBIG) in partnership with the broader cancer community.  The caBIG network is designed to enable the integration and exchange of data among researchers in the laboratory and the clinic, simplify collaboration, and realize the potential of information-based (personalized) medicine in improving patient outcomes. caBIG has connected major components of the cancer community, including NCI-designated Cancer Centers, participating institutions of the NCI Community Cancer Centers Program (NCCCP), and numerous large-scale scientific endeavors, as well as basic, translational, and clinical researchers at public and private institutions across the United States and around the world.  Beyond cancer research, caBIG capabilities—infrastructure, standards, and tools—provide a prototype for linking other disease communities and catalyzing a new 21st-century biomedical ecosystem that unifies research and care. ARRA funding will allow NCI to accelerate the ongoing development of the Cancer Knowledge Cloud and Oncology Electronic Health Records (EHRs) initiatives, thereby providing for continued job creation in the areas of biomedical informatics development and application as well as healthcare delivery.

The caBIG Cancer Knowledge Cloud: Extending the Research Infrastructure

The Cancer Knowledge Cloud is a virtual biomedical capability that utilizes caBIG tools, infrastructure, and security frameworks to integrate distributed individual and organizational data, software applications, and computational capacity throughout the broad cancer research and treatment community. The Cancer Knowledge Cloud connects, integrates, and facilitates sharing of the diverse primary data generated through basic and clinical research and care delivery to enable personalized medicine. The cloud includes information generated through large-scale research projects such as The Cancer Genome Atlas (TCGA), the cancer Human Biobank (caHUB) tissue acquisition network, the NCI Functional Biology Consortium, the NCI Patient Characterization Center, and the NCI Preclinical Development Pipeline, academic and industry counterparts to these projects, and clinical observations (from entities such as the NCCCP) captured in oncology-extended Electronic Health Records.  Through the use of the caBIG Data Sharing and Security Framework, the Cloud will support appropriate sharing of information, supporting in silico hypothesis generation and testing, and enabling a learning healthcare system.

A caBIG-Based Rapid-Learning Healthcare System: Incorporating Oncology-Extended Electronic Healthcare Records (EHRs)

The 21st-century Cancer Knowledge Cloud will connect individuals, organizations, institutions, and their associated information within an information technology-enabled cycle of discovery, development, and clinical care—the paradigm of a rapid-learning healthcare system. This will transform these disconnected sectors into a system that is personalized, preventive, pre-emptive, and patient-participatory.  To be realized, this model requires the adoption of standards-based EHRs. Presently, however, no certified oncology-based EHR exists, and fewer than 3 percent of oncologists with outpatient-based practices utilize EHRs. caBIG has recently established a collaboration with the American Society of Clinical Oncology (ASCO) to develop an oncology-specific EHR (caEHR) specification based on open standards already in use in the oncology community that will utilize caBIG standards for interoperability. NCI will implement an open-source version of this specification to validate the specification and to provide a free alternative to sites that choose not to purchase a commercial system. The launch customer for the caEHR will be NCCCP participating sites. NCI will work with appropriate entities to provide a mechanism for certifying that caEHR implementations are consistent with the NCI/ASCO specification.

Bards Cancer Institute has another clinical bioinformatics program to support their clinical efforts:

Clinical Bioinformatics Program in Oncology at Barts Cancer Institute at Barts and the London School of Medicine

http://www.bci.qmul.ac.uk/cancer-bioinformatics

BCI HomeCancer Bioinformatics

Bards

Why we focus on Cancer Bioinformatics

Bioinformatics is a new interdisciplinary area involving biological, statistical and computational sciences. Bioinformatics will enable cancer researchers not only to manage, analyze, mine and understand the currently accumulated, valuable, high-throughput data, but also to integrate these in their current research programs. The need for bioinformatics will become ever more important as new technologies increase the already exponential rate at which cancer data are generated.

What we do

  • We work alongside clinical and basic scientists to support the cancer projects within BCI.  This is an ideal partnership between scientific experts, who know the research questions that will be relevant from a cancer biologist or clinician’s perspective, and bioinformatics experts, who know how to develop the proposed methods to provide answers.
  • We also conduct independent bioinformatics research, focusing on the development of computational and integrative methods, algorithms, databases and tools to tackle the analysis of the high volumes of cancer data.
  • We also are actively involved in the development of bioinformatics educational courses at BCI. Our courses offer a unique opportunity for biologists to gain a basic understanding in the use of bioinformatics methods to access and harness large complicated high-throughput data and uncover meaningful information that could be used to understand molecular mechanisms and develop novel targeted therapeutics/diagnostic tools.

Developing Criteria for Genomic Profiling in Lung Cancer:

A Report from U.S. Cancer Centers

In a report by Pao et. al., a group of clinicians organized a meeting to standardize some protocols for the integration of microarray and genomic data from lung cancer patients into the clinical setting.[1]  There has been ample evidence that adenocarcinomas could be classified into “clinically relevant molecular subsets” based on distinct genomic changes.  For example EGFR (epidermal growth factor receptor) exon 19 deletions and exon 21 point mutations predict sensitivity to tyrosine kinase inhibitors (TKIs) like gefitinib, whereas exon 20 insertions predict primary resistance[2].

However, as the authors note, “mutational profiling has not been widely accepted or adopted into practice in thoracic oncology”.  

     Therefore, a multi-institutional workshop was held in 2009 among participants from Massachusetts General Hospital (MGH) Cancer Center, Memorial Sloan-Kettering Cancer Center (MSKCC), the Dana-Farber/Bingham & Women’s Cancer Center (DF/BWCC), the M.D. Anderson Cancer Center (VICC), and the Vanderbilt-Ingram Cancer Center (VICC) to discuss their institutes molecular profiling programs with emphasis on:

·         Organization/workflow

·         Mutation detection technologies

·         Clinical protocols and reporting

·         Patient consent

In addition to the aforementioned challenges, the panel discussed further issues for developing improved science-driven criteria for determining targeted therapies including:

1)      Including pathologists into criteria development as pathology departments are usually the main repositories for specimens

2)      Developing integrated informatics systems

3)      Standardizing new target validation methodology across cancer centers

 References

1.            Pao W, Kris MG, Iafrate AJ, Ladanyi M, Janne PA, Wistuba, II, Miake-Lye R, Herbst RS, Carbone DP, Johnson BE et al: Integration of molecular profiling into the lung cancer clinic. Clinical cancer research : an official journal of the American Association for Cancer Research 2009, 15(17):5317-5322.

2.            Wu JY, Wu SG, Yang CH, Gow CH, Chang YL, Yu CJ, Shih JY, Yang PC: Lung cancer with epidermal growth factor receptor exon 20 mutations is associated with poor gefitinib treatment response. Clinical cancer research : an official journal of the American Association for Cancer Research 2008, 14(15):4877-4882.

Other posts on this website on Cancer and Genomics include:

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Progression in Bronchial Dysplasia

Curator and Reporter: Larry H Bernstein, MD, FCAP

 

Genomic evidence of pre-invasive clonal expansion, dispersal and progression in bronchial dysplasia

F McCaughan, CP Pipinikas, SM Janes, PJ George, PH Rabbitts and PH Dear
MRC Laboratory of Molecular Biology, Cambridge, Centre for Respiratory Research, Royal Free and University College Medical School, London, University College London Hospitals, London, Leeds Institute of Molecular Medicine, St James’s University Hospital, Leeds, UK
J Pathol 2011; 224: 153–159   http://dx.doi.org/10.1002/path.2887
http://www.jpathol.com/Genomic evidence of pre-invasive clonal expansion, dispersal and progression in bronchial dysplasia
http://www.ncbi.nlm.nih.gov/pubmed/21506132
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3378694/

The term ‘field cancerization’ is used to describe an epithelial surface that has a propensity to develop cancerous lesions, and in the case of the

  • aerodigestive tract this is often as a result of chronic exposure to carcinogens in cigarette smoke.

The clinical endpoint is the development of multiple tumours,

  • either simultaneously or sequentially in the same epithelial surface.

The mechanisms underlying this process remain unclear; one possible explanation is that

  • the epithelium is colonized by a clonal population of cells that are at increased risk of progression to cancer.

We now address this possibility in a short case series, using individual genomic events as molecular biomarkers of clonality. In squamous lung cancer the most common genomic aberration is 3q amplification. We use a digital PCR technique to

  • assess the clonal relationships between
  • multiple biopsies in a longitudinal bronchoscopic study,
  • using amplicon boundaries as markers of clonality.

We demonstrate that clonality can readily be defined by these analyses and confirm that

  • field cancerization occurs at a pre-invasive stage and that
  • pre-invasive lesions and
  • subsequent cancers are clonally related.

We show that while the amplicon boundaries can be shared between different biopsies,

the degree of 3q amplification and the internal structure of the 3q amplicon varies from lesion to lesion. Finally, in this small cohort, the degree of 3q amplification corresponds to clinical progression.
Keywords: clonality; bronchial dysplasia; molecular copy-number counting
Conflict of interest: A patent for molecular copy-number counting has been applied for by the UK Medical Research Council. Paul Dear is named on the patent application..

The term ‘field cancerization’ was first coined many years ago and the potential underlying biological processes have been studied and discussed at length,

  • particularly in cancers of the aerodigestive tract .

Three possible mechanisms for field cancerization have been mooted in lung cancer.

  • an epithelial surface exposed to repeated insult, such as cigarette carcinogens,
    • could develop multiple separate dysplastic foci that
    • do not originate from a single clone but share similar genetic aberrations
      • as a result of the common carcinogenic insult.
    • In time, one or more of these foci may progress to cancer.
  • a mutant clone expands and migrates to colonize the epithelial surface,
    • without breaching the basement membrane, and
    • molecular divergence results in subclonal populations that may or may not progress.
  • In the third explanation an established cancer spreads to form multifocal clonal tumours.

In the past shared mutations (particularly of TP53 ) or patterns of loss of heterozygosity (LOH) have been the main biomarkers used

  • to infer the presence or absence of a clonal relationship between separate biopsies
  • from a single individual in lung cancer and pre-invasive bronchial dysplasia.

It could be argued that defining a specific shared mutation in TP53,

  • a gene with multiple different mutational hotspots,
  • with or without supportive LOH studies,
  • is more suggestive of clonality than LOH patterns alone.

multiple, anatomically distinct biopsies from an individual with widespread mild dysplasia

  • had a common mutation in TP53,
    • indicating epithelial colonization at a pre-invasive stage.

recently – 70 multifocal lung cancers from 30 individuals suggested,

  • on the basis of both LOH and TP53 mutational analysis,
  • in 77% of individuals the lesions were clonally related.

a digital PCR technique, microdissection molecular copy-number counting (μMCC), can provide detailed high-resolution information on

  • structural genomic events
  • in archived pre-invasive bronchial biopsies, in which
    • the amount of available tissue for analysis is significantly limited and the DNA is of poor quality.

We used this approach to show that 3q amplification is consistently observed in high-grade, but

  • not low-grade, bronchial dysplastic lesions, and that
  • the likely focus of this amplification is SOX2,
    • consistent with recent results from other groups.

This study was prompted by an observation that at very low resolution (2 Mb)

  • a high-grade lesion and
  • a subsequent cancer appeared to share amplicon boundaries.

Therefore, these reasearchers used ultra high-resolution analysis of

  • shared amplicon boundaries
  • to define clonal relationships between
  • microdissected biopsies taken from
  • anatomically distinct parts of the bronchial tree in the same individuals.

Discussion

Field cancerization in the bronchial tree is often described, both in clinical practice and in terms of molecular biomarkers, but the mechanism and natural history of this process remains unclear.  These data, using precisely delineated amplicon boundaries as genomic biomarkers, confirm that

  • clonal expansion and dispersal of cells occurs and that
  • subclonal populations emerge with varying molecular characteristics and clinical outcomes.

A consistent observation in the current cases is that

  • the amplitude of 3q amplification predicts which lesion is likely to progress; and further,
  • there is incremental 3q amplification in those lesions that do progress.

The progression of dysplasia to invasion is generally held to reflect ongoing selection of  clonally advantageous genetic events. However, the contribution of regional genomic events to neoplastic progression is a focus of some debate—whether

  • it is of pathogenic consequence or
  • an epiphenomenon reflecting genome instability.

3q amplification may be

  • selectively neutral or it may be
  • a critical stage in the development of squamous lung cancer.

In support of the latter, the almost uniform finding of 3q amplification in invasive squamous lung cancer

  • its selection in the progression to invasion
    • points to a significant and perhaps obligate role
    • in the pathogenesis of SQC.

Whether SOX2 is the main target of this amplification or one of a number of target oncogenes that are co-amplified remains unclear.

English: Bronchial anatomy detail of alveoli a...

English: Bronchial anatomy detail of alveoli and lung circulation. Français : Anatomie pulmonaire: détail des alvéoles et de la circulation pulmonaires . (Photo credit: Wikipedia)

copy neutral LOH cancer

copy neutral LOH cancer (Photo credit: Wikipedia)

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Genomics of Bronchial Epithelial Dysplasia

Curator: Larry H Bernstein, MD, FCAP

 

C. Walker, LJ Robertson, MW Myskow, N. Pendleton & G.R. Dixon
Clatterbridge Cancer Research Trust, J K Douglas Cancer Research Laboratory, Clatterbridge Hospital, & Broadgreen Hospital, Liverpool, UK.
Br. J. Cancer (1994). 70, 297-303
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2033485/53 expression in normal and dysplastic bronchial epithelium and in lung carcinomas 

Bronchial epithelial dysplasia is thought to be a premalignant stage in the evolution of lung cancers. Using the CM-1 polyclonal antibody, we have examined the expression of the p53 protein in a larger series of bronchial dysplasias (n = 60) than hitherto investigated. The p53 protein was detected in 14% of mild, 25% of moderate and 59% of severe dysplasias; increased p53 expression correlated with the severity of dysplasia. p53-positive dysplasias had greater PCNA indices than p53-negative dysplasias. p53 expression in dysplastic tissues was compared with that in two groups of histologically normal epithelium: 14 bronchial biopsies from non-cancer patients of which all but one were negative and 32 bronchial margins from resected carcinomas, of which 17 showed infrequent solitary cells with p53-positive nuclei in predominantly basal locations scattered throughout the epithelium. These results for resection margins were confirmed by use of a second antibody, DO-1. Sixty-nine per cent of the corresponding carcinomas were p53 positive, but in 15 cases the p53 reactivity differed from resection margins. No correlation between p53 expression and any of the clinicopathological characteristics of these tumours was found. This study supports the observation that abnormal p53 expression may be an early but not obligatory event in malignant transformation in lung.

It is now widely agreed that all lung cancers are derived from a common pluripotent stem cell capable of expressing a variety of phenotypes. Although the sequence of events in the histogenesis of lung cancer is unknown, bronchial epithelial dysplasia is thought to be a premalignant stage in the evolution of lung carcinomas. Multistep genetic changes, which include

  • activation of cellular proto-oncogenes and
  • inactivation of tumour-suppressor genes, are
    • associated with the development of human cancers and are
    • thought to accompany the morphological changes that precede malignancy.

Currently the most commonly identified genetic change in human cancers is mutation in the p53 gene, located at position 13 on the short arm of chromosome 17. This gene is

  • a tumour suppressor gene and
  • encodes a 53 kDa nuclear phosphoprotein
  • capable of binding to DNA and
  • acting as a transcriptional factor.

The wild-type p53 protein inhibits cell proliferation, and

  • loss of this activity leads to neoplastic transformation.

This protein has a

  • short cellular half-life and
  • is usually present in normal cells, under normal physiological conditions, in extremely small amounts,
  • making it undetectable by standard immunohistochemical techniques.

Many mutations of the p53 gene, principally in exons 5-8,

  • lead to a functional inactivation of the -gene and
  • a protein product unable to regulate transcription, ultimately
  • resulting in deregulation of cell growth.

Mutant p53 has

  • an extended cellular half-life
  • enabling immunohistochemical detection of
  • the accumulated mutant protein in cell nuclei.

Although not all mutations lead to protein accumulation, in many studies a correlation between the p53 protein detected immunocytochemically and p53 gene mutations has been found.
Investigation of p53 overexpression in premalignant tissues has led to the observations that

  • alterations in the p53 gene
  • arise as late events in the evolution of some cancers,
    • e.g. in gastric carcinomas, prostatic carcinomas or melanomas, whereas in others,
    • e.g. oral , gall bladder and oesophageal, malignancies, abnormal p53 expression is an early event.

In attempts to define the type and temporal sequence of somatic genetic changes that precede the onset of invasive lung cancer, recent studies have reported mutations and allelic deletions in the p53 gene in preinvasive bronchial lesions. Immunodetectable p53 has been found in a few cases of bronchial dysplasia et al., and Nuorva et al. (1993) have reported that p53 overexpression correlated with the severity of dysplasia in 17 cases of dysplastic epithelium from cancer bearing patients. Thus lesions in the p53 gene have been reported as possible early events in the development of lung cancers.

p53 score and grade of dysplasia

The system of p53 scoring used in these experiments permitted a semiquantitative comparison of the degree of p53 expression in the various tissues examined. With increasing severity of dysplasia there was not only an increase in the percentage of cases demonstrating p53 staining but also an increase in the staining intensity of positive cells and an increase in the proportions of these positive cells. Thus, higher grades of dysplasia were associated with higher p53 scores; the Spearman rank correlation coefficient for the whole table is 0.47 (P = <0.0001), and considering  just the dysplasia cases it is 0.37 (P = 0.002). Comparison of p53 expression between the various grades of dysplasia by use of p53 score  results in more significant P-values by the Mann-Whitney test than obtained with the Fisher-Irwin tests.

PCNA indices

For 39 cases of bronchial dysplasia, PCNA indices had been determined previously (Pendleton et al., 1993). p53-positive dysplasias had significantly greater PCNA indices than p53-negative dysplasias (Table IVa), indicating abnormal growth in these p53-positive biopsies

Bronchial carcinomas and resection margins

In previous studies, a series of bronchial carcinomas (Burnett et al., 1993) and their corresponding resection margins which contained histologically normal epithelium (Pendleton et al., 1993) had been collected prospectively following surgery. Using the CM-1 antibody, p53-positive nuclei were seen in 22/32 (69%) of the tumours and in histologically normal epithelium in 17/32 (53%) of the resection margins (Table V).  p53-positive cells in resection margins were predominantly basal, solitary and scattered throughout the epithelium (Figure 2a), and were less frequent than in tumour tissues (Figure 2b) or many samples of dysplastic epithelium. Many nuclei were weakly stained, but some showed a staining intensity similar to p53-positive tumour cells. Compared with dysplasias and tumour tissues the p53 scores of resection margins were low (Tables III and V), with only one case with a score of 3 and no higher scores. To confirm these results, sections of resection margins were stained with the monoclonal antibody DO-1; all of the cases positive for the CM-1 antibody were also DO-1 positive, but two cases (numbers 16 and 21) which were negative for CM-1 were clearly positive for DO-1.

Discussion

During the course of the preparation of this manuscript, it has been reported that

  • the p53 protein accumulates frequently in early bronchial neoplasia.

This study differs only in that biopsies, not resected tumours, were examined and all tissues were derived from a single treatment centre.  The results of all published studies (p53 expression has so far been investigated in a combined total of 23 mild, 31 moderate and 77 severe dysplasias) yields

  • 19% of the mild,
  • 28% of the moderate and
  • 63% of the severe dysplasias
    • found to be p53 positive.

In other similar studies investigating the expression of the p53 protein in premalignant lesions of lung and other tissues,

  • results were analysed by assessment of p53 positivity.

In this study, analysis was either

    1. by comparison of p53-positive and -negative groups or
    2. by use of a p53 scoring system similar to that described by Vojtesk et al. (1993).

The advantage of this scoring system is that it allows comparison of the degree of p53 expression between tissue groups.
The p53-positive group, equivalent to the positive group in other similar studies,

  • had a p53 score of two or more.

Cells with the p53 score for intensity of 1 were clearly p53 positive and were

  • found in tumours as well as in dysplasias and normal tissues.

Unlike other studies of preinvasive lung lesions,

  • PCNA indices for many of the dysplasias in this series had been determined.

The greater PCNA indices of the p53-positive group

  • indicates that p53-positive dysplasias contain higher proportions of cells in the proliferative phase of the cell cycle;

this suggests that p53-positive dysplasias

  • may have abnormalities in their growth control mechanisms.

It is possible that alterations in the p53 gene confer a growth advantage on these cells, leading to

  • expansion of p53-positive cells as severity of dysplasia increases.

A close relation between p53 overexpression and PCNA indices has also been observed in

  • pancreatic duct cell carcinomas,
  • hepatocellular carcinomas, and
  • gastric cancers.

In this study, p53 expression in dysplastic tissues was

  • compared with two groups of histologically normal epithelium.

All but one of the first group, taken from patients who did not have cancer at the time of biopsy, were negative. Comparison of p53 expression in this group with that in

  • dysplastic bronchial biopsies
    • showed a highly significant difference between these groups.

The second group of histologically normal epithelium analysed,

  • from the resection margins of bronchial carcinomas,
    • showed p53-positive cells in a high proportion of cases,
      • indicating differences in the normal bronchial epithelium of cancer and non-cancer patients.

p53 positivity in the normal mucosa of resection margins did not result in a measurable increase in proliferation, as indicated by PCNA indices. This may suggest that the mechanism whereby the p53 protein is elevated in normal mucosa differs from that in dysplasia. Whatever the mechanism to account for these p53-positive cells in normal bronchial mucosa, it seems that their presence, even if not associated with mutation in the p53 gene, indicates abnormalities that are not reflected in the histological appearance of these cells.

The number of p53-positive tumours in the series (69% overall and 68% for non-small-cell lung cancers) agreed well

  • with the incidence of p53 positivity for lung cancers reported in some studies
  • but was higher than that found in others.

Although the number of tumours in this series was small no correlation in p53 overexpression was found with any of the clnical characteristics of these tumours. This contrasts with reports of a relationship between p53 overexpression and

  • poor prognosis and shortened survival,
  • tumour grade  or lymph node involvement and
  • a greater incidence in squamous cell carcinomas compared with other types of lung carcinoma .

This study supports the observation that abnormal p53 expression is an early but not obligatory event in the evolution of lung cancers. Immunodetection of p53 overexpression in bronchial epithelium

    • may be a useful tool in the identification of those early lesions which may progress to malignancy.

Age-standardised death rates from Trachea, bro...

Age-standardised death rates from Trachea, bronchus, lung cancers by country (per 100,000 inhabitants). (Photo credit: Wikipedia)

 

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Personalized Medicine in NSCLC

Reviewer: Larry H Bernstein, MD, FCAP

Introduction

Early in the 21st century, gefitinib, an epi­dermal growth factor receptor (EGFRtyrosine kinase inhibitor became available  for the treatment of non-small cell lung can­cer (NSCLC). Over 80% of selected patients

  • EGFR mutation-positive patients, respond to gefitinib treatment;
  • most patients develop acquired resistance to gefitinib within a few years.
Recently, many studies have been performed to determine precisely how to select patients who will respond to gefitinib, the best timing for its administration, and how to avoid the development of acquired resistance as well as adverse drug effects.
Lung cancers are classified according to their his­tological type. Because each variant has different bio­logical and clinical properties, including response to treatment, a precise classification is essential to pro­vide appropriate therapy for individual patients. Lung cancer consists of two broad categories—non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC).

NSCLC  – 20%–40% RR to chemotherapy

  • ade­nocarcinoma (AC),  40%–50% ( most common form)
    • higher sensitivity to chemotherapy than SCC or LC
  • squamous cell carcinoma (SCC),  ∼30%
  •  large cell carcinoma (LCC). 10%
The majority of patients with SCLC are diagnosed with
  • advanced cancer with distant metastasis
  • high sensitivity to chemotherapy.
  • response rate (RR) for SCLC is reportedly 60%–80%
  • complete remission is observed in only 15%–20% of patients
The Potential of Personalized Medicine in Advanced NSCLC
Personalized medicine—
  • matching a patient’s unique molecular profile with an appropriate targeted therapy—
  • is transforming the diagnosis and treatment of non–small-cell lung cancer (NSCLC).

Through molecular diagnostics, tumor cells may be differentiated based on the presence or absence of

  • receptor proteins,
  • driver mutations, or
  • oncogenic fusion/rearrangements.

The convergence of advancing research in drug development and genetic sequencing has permitted the development of therapies specifically targeted to certain biomarkers, which may offer a differential clinical benefit.

Putting personalized medicine in NSCLC into practice
With the data on the prognostic and predictive biomarkers EGFR and ALK, biomarker testing is increasingly important in therapy decisions in NSCLC.1,2
Biomarker Testing in Advanced NSCLC: Evolution in Pathology Clinical Practice
http://www.medscape.com/infosite/letstest/article-3
Multidisciplinary Approaches in the Changing Landscape of Advanced NSCLC
http://www.medscape.com/infosite/letstest/article-4
Oncology Perspectives on Biomarker Testing
http://www.medscape.com/infosite/letstest/article-1

References
1. National Comprehensive Cancer Network (NCCN). NCCN Clinical Practice Guidelines in Oncology™: Non-Small Cell Lung Cancer. Version 2.2012.
http://www.nccn.org/professionals/physician_gls/PDF/nscl.pdf.                   August 6, 2012.
2. Gazdar AF. Epidermal growth factor receptor inhibition in lung cancer: the evolving role of individualized therapy. Cancer Metastasis Rev. 2010;29(1):37-48.

Over the last decade, a growing number of biomarkers have been identified in NSCLC.3,4 To date, 2 of these molecular markers have been shown to have both prognostic and predictive value in patients with advanced NSCLC: epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangements.5-8 Testing for these biomarkers may provide physicians with more information on which to base treatment decisions, and reflex testing may permit consideration of appropriate therapy from the outset of treatment.2,9,10

References:
Lovly CM, Carbone DP. Lung cancer in 2010: one size does not fit all. Nat Rev Clin Oncol. 2011;8(2):68-70.
Dacic S. Molecular diagnostics of lung carcinomas. Arch Pathol Lab Med. 2011;135(5):622-629.
Herbst RS, Heymach JV, Lippman SM. Lung cancer. N Engl J Med. 2008;359(13):1367-1380.
Quest Diagnostics. Lung Cancer Mutation Panel (EGFR, KRAS, ALK).                       Sept 17, 2012
http://questdiagnostics.com/hcp/intguide/jsp/showintguidepage.jsp?fn=Lung/TS_LungCancerMutation_Panel.htm.

Rosell R, Gervais R, Vergnenegre A, et al. Erlotinib versus chemotherapy (CT) in advanced non-small cell lung cancer (NSCLC) patients (p) with epidermal growth factor receptor (EGFR) mutations: interim results of the European Erlotinib Versus Chemotherapy (EURTAC) phase III randomized trial. Presented at: 2011 American Society of Clinical Oncology (ASCO) Annual Meeting, J Clin Oncol. 2011;29(suppl). Abstract 7503.                        Aug 6, 2012.                    http://www.asco.org/ASCOv2/Meetings/Abstracts?&vmview=abst_detail_view&confID=102&abstractID=78285.
Mok TS, Wu YL, Thongprasert S, et al. Gefitinib or carboplatin-paclitaxel in pulmonary adenocarcinoma. N Engl J Med. 2009;361(10):947-957.
Kwak EL, Bang YJ, Camidge DR, et al. Anaplastic lymphoma kinase inhibition in non–small-cell lung cancer. N Engl J Med. 2010;363(18):1693-1703.
National Comprehensive Cancer Network (NCCN). NCCN Clinical Practice Guidelines in Oncology™: Non-Small Cell Lung Cancer. Version 2.2012.
http://www.nccn.org/professionals/physician_gls/PDF/nscl.pdf.                        Aug 6, 2012
College of American Pathologists (CAP)/International Association for the Study of Lung Cancer (IASLC)/Association for Molecular Pathology (AMP) expert panel. Lung cancer biomarkers guideline draft recommendations. http://capstaging.cap.org/apps/docs/membership/transformation/new/lung_public_comment_supporting_materials.pdf.      Aug 6, 2012.
Gazdar AF. Epidermal growth factor receptor inhibition in lung cancer: the evolving role of individualized therapy. Cancer Metastasis Rev. 2010;29(1):37-48.

 Background Studies
In 2002, gefitinib (ZD1839; AstraZeneca) , the first epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, became available as an innovative molecular-targeted drug for the treatment of unresectable NSCLC. Initially, many NSCLC patients were expected to respond to gefitinib because many solid tumors, including NSCLC, are known to overexpress EGFR, which has a role in tumor pro­liferation and is used as a biomarker to predict poor prognosis. Gefitinib was shown to have a dra­matic effect on a limited number of patients; but  it was ineffective in 70%–80% of patients with NSCLC. There have been reports of death caused by interstitial pneumonia (IP), one of the critical adverse drug reactions (ADRs) associated with gefitinib use. Therefore, there is a need for  predicting the effects of gefitinib, and criteria for select­ing patients who could be treated with gefitinib.
 In 2004, Lynch et al. and Paez et al. each pub­lished, on the same day, sensational reports in the New England Journal of Medicine and Science, identifying somatic mutations in the tyrosine kinase domain of the EGFR gene in patients with gefitinib-sensitive lung cancer, as compared with none of the patients who had no response. Therefore, screening for EGFR mutations in lung cancer showed potential for identifying patients who would respond to gefi­tinib therapy. It then was found that patients with EGFR mutations in the area of the gene cod­ing for the ATP-binding pocket of the tyrosine kinase domain responded to gefitinib. Consequently, the EGFR genotyping has been used to select patients who will respond to gefitinib. Other genetic mutations have also been reported as indicators of the response or resistance to gefitinib; for example, mutations of the KRAS gene are associated with primary resistance to gefitinib. Thus, screening of EGFR and KRAS is used to
  • predict the effects of gefi­tinib and
  • to select patients who will respond to gefitinib in the clinical setting.
Until now, the effects of gefitinib have been predicted only by genotyping factors, such as EGFR and KRAS mutations. However, Nakamura et al showed a relationship between the blood concentration of gefitinib and its clinical effects. In their study of 23 NSCLC patients with EGFR mutations, the ratio of the gefitinib concentration on day 8 to that on day 3 after the first administration of gefitinib (C8/C3) correlated with the progression-free survival (PFS) period. Patients with a higher C8/C3 ratio had a significantly lon­ger PFS (P = 0.0158, 95% confidence interval [CI]: 0.237–0.862), which  suggests the importance of the PK of gefitinib on its clinical outcome.   Chmielecki et al. concurrently reported that maintain­ing a high concentration of erlotinib, another EGFR tyrosine kinase inhibitor (EGFR-TKIs) with the same mechanism of action as gefitinib, could
  1. delay the establishment of drug-resistant tumor cells and
  2. decrease the proliferation rate of drug-resistant cells compared to
    • treatment using a lower concentration of erlotinib.
Pharmacogenetic profile
Initially, gefitinib was expected to induce a response in patients with tumors that overexpressed EGFR because it exerts its antineoplastic effects by com­petitively inhibiting the binding of ATP to the ATP-binding site of EGFR.  A number of studies contradict this hypothesis:
(1) while approxi­mately 40%–80% of NSCLC overexpress EGFR, only 10%–20% of NSCLC patients respond to gefi­tinib;5,6 and
(2) while EGFR overexpression is known to be more common in SCC than AC, gefitinib shows a higher antineoplastic effect on AC than on SCC, while other reports indicated no correlation between the expression levels of EGFR and clinical outcomes.
In 2004, somatic mutations were identified in the EGFR tyrosine kinase domain of patients with gefitinib-responsive lung cancer, as compared with no mutations in patients exhibiting no response, and the presence of an EGFR mutation was highly correlated with a good response to gefitinib.The conformational change of the EGFR ATP-binding site caused by genetic mutations constitutively acti­vates the EGFR downstream signaling pathway and increases the malignancy of cancer. Conversely, the conformational change of the ATP-binding site can also increase its affinity for gefitinib; therefore, gefi­tinib can inhibit the downstream signaling pathway more easily, strongly induces apoptosis, and reduces the proliferation of cancer cells.
Mutations in exons 18–21 of EGFR are predictive factors for the clinical efficacy of gefitinib;
  • deletions in exon 19 and missense mutations in exon 21 account for ∼90% of these mutations.

The detection of EGFR muta­tions in exons 19 and 21 is considered to be essential to predict the clinical efficacy of gefitinib.
Acquired resistance
All responders eventually develop resistance to gefitinib but in 2005, an EGFR mutation in exon 20, which substitutes methionine for threonine at amino acid position 790 (T790M), was reported to be one of the main causes of acquired resistance to gefitinib. The EGFR T790M vari­ant

  1. changes the structural conformation of the ATP-binding site, thereby
  2. increasing the affinity of ATP to EGFR, while
  3. the affinity of gefitinib to ATP is unchanged.

Screening methods for EGFR and KRAS mutations
The detection of EGFR and KRAS mutations has been usually achieved by sequencing DNA amplified from tumor tissues; however, sequencing techniques are too complex, time-consuming, and expensive.  The selection of an appropri­ate method to detect EGFR and KRAS mutations is essential to make an exact prediction of the efficacy of gefitinib in individual patients. Advances in diagnostics and treatments for NSCLC have led to better outcomes and higher standards of what outcomes are expected. These new understandings and treatments have raised multiple new questions and issues with regard to the decisions on the appropriate treatment of NSCLC patients.

  • Biomarkers are increasingly recognized and applied for guidance in diagnosis, prognosis and treatment decisions and evaluation.
  • Biologics and newer cancer treatments are enabling the possibility for new combined treatment modalities in earlier stage disease
  • Maintenance therapy has been shown to be useful, but optimal therapy choices before and after maintenance therapy need clarification
  • The importance of performance status on treatment decisions
  • Comparative effectiveness is becoming an expectation across all treatments and diseases, and will prove difficult to accomplish within the complexity of cancer diseases
NCCN Molecular Testing White Paper: Effectiveness, Efficiency, and Reimbursement
PF Engstrom, MG Bloom,GD Demetri, PG Febbo, et al.
Personalized medicine in oncology is maturing and evolving rapidly, and the use of molecular biomarkers in clinical decisionmaking is growing. This raises important issues regarding the safe, effective, and efficient deployment of molecular tests to guide appropriate care, specifically regarding laboratory-developed tests and companion diagnostics. In May 2011, NCCN assembled a work group composed of thought leaders from NCCN Member Institutions and other organizations to identify challenges and provide guidance regarding molecular testing in oncology and its corresponding utility. The NCCN Molecular Testing Work Group identified
challenges surrounding molecular testing, including health care provider knowledge, determining clinical utility, coding and billing for molecular tests, maintaining clinical and analytic validity of molecular tests, efficient use of specimens, and building clinical evidence. (JNCCN 2011;9[Suppl 6]:S1–S16)
Executive Summary
The FDA recently announced plans for oversight of laboratory-developed tests (LDTs) and released draft guidance regarding the development of companion diagnostics concurrently with therapeutics, both areas over which the FDA has regulatory authority. As recognized by the FDA, these types of diagnostic tests are used increasingly to directly inform treatment decisions, and this especially impacts patients with cancer and their oncologists. However, because of the increasing complexity of some LDTs and increasing commercial interest in oncology-related LDTs in general, the FDA is considering whether its policy of exercising “enforcement discretion”

for LDTs is still appropriate. To provide guidance regarding challenges of molecular testing to health care providers and other stakeholders, NCCN assembled a work group composed of thought leaders from NCCN Member Institutions and other organizations external to NCCN.  The NCCN Molecular Testing Work Group agreed to define molecular testing in oncology as

  • procedures designed to detect somatic or germline mutations in DNA and
  • changes in gene or protein expression that could impact the
    • diagnosis,
    • prognosis,
    • prediction, and
    • evaluation of therapy of patients with cancer.
Therefore, the discussion focused on molecular tests that predict outcomes for therapy.
Realizing the importance of personalized medicine in advanced NSCLC
E Topol, B Buehler, GS Ginsburg.       Medscape Molec Medicine
With the data on the prognostic and predictive biomarkers EGFR and ALK, biomarker testing is increasingly important in therapy decisions in NSCLC
http://www.nccn.org/professionals/physician_gls/PDF/nscl.pdf/
Lung Cancer in the Never Smoker Population: An Expert Interview With Dr. Nasser Hanna

Lung cancer in the never smoker population is a distinct disease entity with specific molecular changes, offering the potential for targeted therapy.
Experts And Viewpoint, Medscape Hematology-Oncology, December 2007

An Update on New and Emerging Therapies for NSCLC
Simon L. Ekman, MD, PhD; Fred R. Hirsch, MD, PhD
On completion of these readings participants will be thoroughly familiar with these issues:
  1. The influence of histologic types and genetic and molecular markers on choosing and personalizing therapy in patients with advanced NSCLC
  2. The role of the pathologist in properly classifying subtypes of NSCLC and reporting the presence of molecular markers in tumor samples
  3. Familiarize themselves with effective methods of obtaining adequate tissue samples from patients and recognize the importance of accurate pathologic assessment of NSCLC
The rapid developments in molecular biology have opened up new possibilities for individualized treatment of non-small cell lung cancer (NSCLC), and, in recent years, has mainly focused on the epidermal growth factor receptor (EGFR). A greater understanding of the molecular mechanisms behind
  • tumorigenesis and
  • the identification of new therapeutic targets
    • have sparked the development of novel agents
    • intended to improve the standard chemotherapy regimens for NSCLC.
Along with the advent of targeted therapy, identifying biomarkers to predict the subset of patients more likely to benefit from a specific targeted intervention has become increasingly important.
EGFR TYROSINE KINASE INHIBITORS 
tumor-associated mutations in the tyrosine kinase domain of EGFR have been associated with response to EGFR TKIs
The most common EGFR-sensitizing mutations encompass deletions in exon 19 and a point mutation at L858R in exon 21; together,
  • they account for approximately 85% of EGFR mutations in NSCLC.
  • Other EGFR mutations have been detected, particularly in exon 20.
    •  mutations identified in exon 20 have been linked to resistance to EGFR TKIsNon-Small Cell Lung Cancer: Biologic and Therapeutic Considerations for Personalized Management
      Taofeek K. Owonikoko, MD, PhD
What is the role and application of molecular profiling in the management of NSCLC?
It is essential to:
  1. Identify advances in the understanding of molecular biology and histologic profiling in the treatment of NSCLC
  2. Summarize clinical data supporting the use of tumor biomarkers as predictors of therapeutic efficacy of targeted agents in NSCLC
  3. Devise an individualized treatment plan for patients with advanced NSCLC based on a tumor’s molecular profile
  4. Identify methods for overcoming barriers to effective incorporation of molecular profiling for the management of NSCLC into clinical practice
Non-small cell lung cancer (NSCLC),the most common type of lung cancer, usually grows and spreads more slowly than small cell lung cancer.
The three common forms of NSCLC are:
  1. Adenocarcinomas are often found in an outer area of the lung.
  2. Squamous cell carcinomas are usually found in the center of the lung next to an air tube (bronchus).
  3. Large cell carcinomas occur in any part of the lung and tend to grow and spread faster than the other two types
Smoking causes most cases of lung cancer. The risk depends on the number of cigarettes you smoke every day and for how long you have smoked. Some people who do not smoke and have never smoked develop lung cancer.
Working with or near the following cancer-causing chemicals or materials can also increase your risk:
  • Asbestos
  • Chemicals such as uranium, beryllium, vinyl chloride, nickel chromates, coal products, mustard gas, chloromethyl ethers, gasoline, and diesel exhaust
  • Certain alloys, paints, pigments, and preservatives
  • Products using chloride and formaldehyde
Non-small cell lung c

ancer
(NSCLC) accounts for
  • approximately 85% of all lung cancers.
Lung cancer  may produce no symptoms until the disease is well advanced, so early recognition of symptoms may be beneficial to outcome.
At initial diagnosis,
  • 20% of patients have localized disease,
  • 25% of patients have regional metastasis, and
  • 55% of patients have distant spread of disease.
Revisiting Doublet Maintenance Chemo in Advanced NSCLC 
H. Jack West, MD
  • Pemetrexed Versus Pemetrexed and Carboplatin as Second-Line Chemotherapy In Advanced Non-Small-Cell Lung Cancer
Ardizzoni A, Tiseo M, Boni L, et al
J Clin Oncol. 2102;30:4501-4507
Historically, our second-line therapy has evolved into a strategy of pursuing single-agent therapies for patients with advanced non-small cell lung cancer (NSCLC) who have received prior chemotherapy. This approach was developed on the basis of benefits conferred by such established treatments as docetaxel, pemetrexed, and erlotinib — each well-tested as single agents — and evidence indicating a survival benefit in previously treated patients.
A study out of Italy by Ardizzoni and colleagues published in the Journal of Clinical Oncology directly compares carboplatin/pemetrexed with pemetrexed alone, and
  • it provides more evidence that our current approach of sequential singlet therapy remains appropriate.
This randomized phase 2 trial enrolled 239 patients with advanced NSCLC, initially of any histology, then later amended (September 2008) to enroll
  • only patients with non-squamous NSCLC because of mounting evidence that pemetrexed is not active in patients with the squamous subtype of advanced NSCLC.
Patients must have received prior chemotherapy (without restriction on regimen except that it could not include pemetrexed). Participants were randomly assigned 1:1 to receive pemetrexed at the standard dose of 500 mg/m2 IV every 21 days or the same chemotherapy with carboplatin at an area under the curve of 5, also IV every 21 days.
The primary endpoint for the trial was progression-free survival (PFS), and the trial was intended to have results pooled with a nearly identically designed trial that was done in The Netherlands. The Dutch trial compared pemetrexed with carboplatin/pemetrexed at the same dose and schedule. The vast majority of patients (97.5%) had a performance status of 0 or 1, and the median age was 64 years.
The Italian study found no evidence to support a benefit in efficacy from the more aggressive doublet regimen. Specifically,
  • median PFS was 3.6 months with pemetrexed alone vs 3.5 months with carboplatin/pemetrexed.
  • Response rate (RR) and median overall survival (OS) were also no better with the doublet regimen
      • RR 12.6% vs 12.5%, median OS 9.2 vs 8.8 months, for pemetrexed and carboplatin/pemetrexed.

Moreover, pooling the data from the Italian trial with the Dutch trial demonstrated no significant differences between the 2 strategies. Subgroup analysis showed that

  • the patients with squamous NSCLC had a superior median PFS of 3.2 months with the carboplatin doublet vs 2.0 months with pemetrexed alone.

Unfortunately, this only confirms that adding a second agent is beneficial for patients receiving an agent previously shown to be ineffective in that population.

Viewpoint
Putting it in the context of previous data, these results only provide further confirmation that more is not better.
  • combinations are associated with more toxicity than single-agent therapy, and
  • this is likely to be especially relevant in previously treated patients whose ability to tolerate ongoing therapy over time may be reduced.

It is critical to balance efficacy with tolerability to enable us to deliver the treatment over a prolonged period. We need to recognize the importance of pacing ourselves if our goal is to administer treatments in a palliative setting for an increasingly longer duration.

Epidermal growth factor receptor (EGFR) signal...

Epidermal growth factor receptor (EGFR) signaling pathway. (Photo credit: Wikipedia)

EGFR structure

EGFR structure (Photo credit: Wikipedia)

ATP synthase

ATP synthase (Photo credit: Ethan Hein)

Non-small cell carcinoma - FNA

Non-small cell carcinoma – FNA (Photo credit: Pulmonary Pathology)

Articles on NSCLC in Pharmaceutical Intelligence:
Key Sources:
  1. Realizing the importance of personalized medicine in advanced NSCLC
    E Topol, B Buehler, GS Ginsburg. 

    Medscape Molec Medicine The Potential of Personalized Medicine in Advanced NSCLC

    With the data on the prognostic and predictive biomarkers EGFR and ALK, biomarker testing is increasingly important in therapy decisions in NSCLC
  2. Revisiting Doublet Maintenance Chemo in Advanced NSCLC
    H. Jack West, MD     http://www.medscape.com/viewarticle/777367
    Pemetrexed Versus Pemetrexed and Carboplatin as Second-Line Chemotherapy In Advanced Non-Small-Cell Lung Cancer
    Ardizzoni A, Tiseo M, Boni L, et al
    J Clin Oncol. 2102;30:4501-4507
  3. Lung Cancer in the Never Smoker Population: An Expert Interview With Dr. Nasser Hanna
    Experts And Viewpoint, Medscape Hematology-Oncology, December 2007
  4. Non-Small Cell Lung Cancer: Biologic and Therapeutic Considerations for Personalized Management
    Taofeek K. Owonikoko, MD, PhD   August 24, 2011.   Medscape
  5. An Update on New and Emerging Therapies for NSCLC
    Simon L. Ekman, MD, PhD; Fred R. Hirsch, MD, PhD     Medscape
  6. Lovly CM, Carbone DP. Lung cancer in 2010: one size does not fit all. Nat Rev Clin Oncol. 2011;8(2):68-70.
  7. Dacic S. Molecular diagnostics of lung carcinomas. Arch Pathol Lab Med. 2011;135(5):622-629.

  8. Herbst RS, Heymach JV, Lippman SM. Lung cancer. N Engl J Med. 2008;359(13):1367-1380.
  9. Gazdar AF. Epidermal growth factor receptor inhibition in lung cancer: the evolving role of individualized therapy.

    Cancer Metastasis Rev. 2010;29:37-48.

  10. NCCN Oncology Insights Report on Non-Small Cell Lung Cancer 1.2010
  11.   Review of the Treatment of Non-Small Cell Lung Cancer with Gefitinib
    T Araki, H Yashima, K Shimizu, T Aomori
    Clinical Medicine Insights: Oncology 2012:6 407–421  http://dx.doi.org/10.4137/CMO.S7340

 

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State of the art in oncologic imaging of lungs.

Author and Curator: Dror Nir, PhD

This is the second post in a series in which I will address the state of the art in oncologic imaging based on a review paper; Advances in oncologic imaging that provides updates on the latest approaches to imaging of 5 common cancers: breast, lung, prostate, colorectal cancers, and lymphoma. This paper is published at CA Cancer J Clin 2012. © 2012 American Cancer Society.

The paper gives a fair description of the use of imaging in interventional oncology based on literature review of more than 200 peer-reviewed publications.

In this post I summaries the chapter on lung cancer imaging.

Lung Cancer Imaging

“Lung cancer remains the most common cause of death from cancer worldwide, having resulted in 1.38 million deaths (18.2% of all cancer deaths) in 2008.48 It also represents the leading cause of death in smokers and the leading cause of cancer mortality in men and women in the United States. In 2012, it was estimated that 226,160 new cases of lung cancer would be diagnosed (accounting for about 14% of cancer diagnoses) and that lung cancer would cause 160,340 deaths (about 29% of cancer deaths in men and 26% of cancer deaths in women) in the United States.1 The 1-year relative survival rate for the disease increased from 35% to 43% from 1975 through 1979 to 2003 through 2006.49 The 5-year survival rate is 53% for disease that is localized when first detected, but only 15% of lung cancers are diagnosed at this early stage.”

For cancer with such poor survival rates removal of the primary lesion by surgery at an early-stage disease is the best option. The current perception in regards to lung cancr is that patients may have subclinical disease for years before presentation. It is also known that early lung cancer lesions; adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) are slow-growing, doubling time which can exceed 2 years.52 But, since at present, no lung cancer early-detection biomarker is clinically available, the diagnosis of this disease is primarily based on symptoms, and detection often occurs after curative intervention and when it’s already too late – see: Update on biomarkers for the detection of lung cancer and also Diagnosing lung cancer in exhaled breath using gold nanoparticles. Until biomarker is found, the burden of screening for this disease is on imaging.

“AIS and MIA generally appear as a single peripheral ground-glass nodule on CT. A small solid component may be present if areas of alveolar collapse or fibroblastic proliferation are present,5051 but any solid component should raise concern for a more invasive lesion (Fig. 8). Growth over time on imaging can often be difficult to assess due to the long doubling time of these AIS and MIA, which can exceed 2 years.52 However, indicators other than growth, such as air bronchograms, increasing density, and pleural retraction within a ground-glass nodule are suggestive of AIS or MIA.

CT image shows a ground glass nodule, which is the typical appearance of AIS, in the right upper lobe.

CT image shows a ground glass nodule, which is the typical appearance of AIS, in the right upper lobe.

 

CT (A) demonstrated extensive consolidation with air bronchograms in the left upper lobe, which at surgical resection were found to represent adenocarcinoma of mixed subtype with predominate (70%) mucinous bronchioloalveolar subtype. PET imaging in the same patient (B) demonstrated uptake in the lingula higher than expected for bronchioloalveolar carcinoma and probably due to secondary inflammation/infection. CT (C) obtained 3 years after images (A) and (B) demonstrated biopsy-proven recurrent soft-tissue mass near surgical site. Fused FDG/PET images (D) demonstrate no uptake in the area. This finding is consistent with the decreased uptake usually seen in tumors of bronchioloalveolar histology (new terminology of MIA).

CT (A) demonstrated extensive consolidation with air bronchograms in the left upper lobe, which at surgical resection were found to represent adenocarcinoma of mixed subtype with predominate (70%) mucinous bronchioloalveolar subtype. PET imaging in the same patient (B) demonstrated uptake in the lingula higher than expected for bronchioloalveolar carcinoma and probably due to secondary inflammation/infection. CT (C) obtained 3 years after images (A) and (B) demonstrated biopsy-proven recurrent soft-tissue mass near surgical site. Fused FDG/PET images (D) demonstrate no uptake in the area. This finding is consistent with the decreased uptake usually seen in tumors of bronchioloalveolar histology (new terminology of MIA).

In August 2011 the results of the “National Lung Screening Trial “ which was funded by the National Cancer Institute (NCI) were published in NEJM; Reduced Lung-Cancer Mortality with Low-Dose Computed Tomographic Screening. This randomized study results showed that with low-dose CT screening of high-risk persons, there was a significant reduction of 20% in the mortality rate from lung cancer as compared to chest radiographs screening.

Based on these results one can find the following information regarding Lung Cancer Screening on the NCI web-site:

Three screening tests have been studied to see if they decrease the risk of dying from lung cancer.

The following screening tests have been studied to see if they decrease the risk of dying from lung cancer:

  • Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
  • Sputum cytology: Sputum cytology is a procedure in which a sample of sputum (mucus that is coughed up from the lungs) is viewed under a microscope to check for cancer cells.
  • Low-dose spiral CT scan (LDCT scan): A procedure that uses low-dose radiation to make a series of very detailed pictures of areas inside the body. It uses an x-ray machine that scans the body in a spiral path. The pictures are made by a computer linked to the x-ray machine. This procedure is also called a low-dose helical CT scan.

Screening with low-dose spiral CT scans has been shown to decrease the risk of dying from lung cancer in heavy smokers.

A lung cancer screening trial studied people aged 55 years to 74 years who had smoked at least 1 pack of cigarettes per day for 30 years or more. Heavy smokers who had quit smoking within the past 15 years were also studied. The trial used chest x-rays or low-dose spiral CT scans (LDCT) scans to check for signs of lung cancer.

LDCT scans were better than chest x-rays at finding early-stage lung cancer. Screening with LDCT also decreased the risk of dying from lung cancer in current and former heavy smokers.

Guide is available for patients and doctors to learn more about the benefits and harms of low-dose helical CT screening for lung cancer.

Screening with chest x-rays or sputum cytology does not decrease the risk of dying from lung cancer.

Chest x-ray and sputum cytology are two screening tests that have been used to check for signs of lung cancer. Screening with chest x-ray, sputum cytology, or both of these tests does not decrease the risk of dying from lung cancer.

The authors of Advances in oncologic imaging found out that for pre-treatment staging and post treatment follow-up of lung cancer patients mainly involves CT (preferably contrast enhanced, FDG PET and PET/CT. “Integrated PET/CT has been found to be more accurate than PET alone, CT alone, or visual correlation of PET and CT for staging NSCLC (Non-small-cell lung carcinoma).59 “

The standard treatment of choice for localized disease remains surgical resection with or without chemo-radiation therapy (stage dependant). “The current recommendations for routine follow-up after complete resection of NSCLC are as follows: for 2 years following surgery a contrast-enhanced chest CT scan every 4 to 6 months and then yearly non-contrast chest CT scans.62 Detection of recurrence on CT is the primary goal in the initial years, and therefore, optimally, a contrast-enhanced scan should be obtained to evaluate the mediastinum. In subsequent years, when identifying an early second primary lung cancer becomes of more clinical importance, a non-contrast CT chest scan suffices to evaluate the lung parenchyma.

CT (A) of 78-year-old male who was status post–left lobe lobectomy and left upper lobe wedge resection shows recurrent nodule at the surgical resection site. Fused PET/CT (B) demonstrates increased [18F]FDG uptake in the corresponding nodule at the surgical resection site consistent with recurrent tumor.

CT (A) of 78-year-old male who was status post–left lobe lobectomy and left upper lobe wedge resection shows recurrent nodule at the surgical resection site. Fused PET/CT (B) demonstrates increased [18F]FDG uptake in the corresponding nodule at the surgical resection site consistent with recurrent tumor.

In patients undergoing chemotherapies: “ [18F]FDG PET response correlates with histologic response.63 [18F]FDG PET scan data can provide an early readout of response to chemotherapy in patients with advanced-stage lung cancer.64

In patients treated by recently developed “Targeted Therapies” such as Radiofrequency ablation (RFA) the authors found out that PET/CT is the preferred imaging modality for post treatment follow-up.

“ Most patients treated with pulmonary ablation will have had a pre-procedure CT or a fusion PET/CT scan, which allows more precise anatomic localization of abnormalities seen on PET. Generally, either CT or PET/CT is performed within a few weeks of the procedure to provide a new baseline to which future images can be compared to assess for changes in size, degree of enhancement or [18F]FDG avidity.67

CT (A) demonstrates new left upper lobe mass representing new primary NSCLC in a patient who had a status post–right pneumonectomy for a prior NSCLC. CT (B) obtained in the same patient 2 weeks after radiofrequency ablation (RFA) demonstrates the postablation density in the left upper lobe. Fused PET/CT (C) obtained 4 months after RFA demonstrates mild [18F]FDG uptake at RFA site in the left upper lobe consistent with posttreatment inflammation. Fused PET/CT (D) obtained 7 months after RFA demonstrates new focal [18F]FDG uptake at post-RFA-opacity consistent with recurrent tumor.

CT (A) demonstrates new left upper lobe mass representing new primary NSCLC in a patient who had a status post–right pneumonectomy for a prior NSCLC. CT (B) obtained in the same patient 2 weeks after radiofrequency ablation (RFA) demonstrates the postablation density in the left upper lobe. Fused PET/CT (C) obtained 4 months after RFA demonstrates mild [18F]FDG uptake at RFA site in the left upper lobe consistent with posttreatment inflammation. Fused PET/CT (D) obtained 7 months after RFA demonstrates new focal [18F]FDG uptake at post-RFA-opacity consistent with recurrent tumor.

Prostate Cancer Imaging

To be followed…

Other research papers related to the management of Lung cancer were published on this Scientific Web site:

Diagnosing lung cancer in exhaled breath using gold nanoparticles

Lung Cancer (NSCLC), drug administration and nanotechnology

Non-small Cell Lung Cancer drugs – where does the Future lie?

Comprehensive Genomic Characterization of Squamous Cell Lung Cancers

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