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Imaging-guided cancer treatment


Imaging-guided cancer treatment

Writer & reporter: Dror Nir, PhD

It is estimated that the medical imaging market will exceed $30 billion in 2014 (FierceMedicalImaging). To put this amount in perspective; the global pharmaceutical market size for the same year is expected to be ~$1 trillion (IMS) while the global health care spending as a percentage of Gross Domestic Product (GDP) will average 10.5% globally in 2014 (Deloitte); it will reach ~$3 trillion in the USA.

Recent technology-advances, mainly miniaturization and improvement in electronic-processing components is driving increased introduction of innovative medical-imaging devices into critical nodes of major-diseases’ management pathways. Consequently, in contrast to it’s very small contribution to global health costs, medical imaging bears outstanding potential to reduce the future growth in spending on major segments in this market mainly: Drugs development and regulation (e.g. companion diagnostics and imaging surrogate markers); Disease management (e.g. non-invasive diagnosis, guided treatment and non-invasive follow-ups); and Monitoring aging-population (e.g. Imaging-based domestic sensors).

In; The Role of Medical Imaging in Personalized Medicine I discussed in length the role medical imaging assumes in drugs development.  Integrating imaging into drug development processes, specifically at the early stages of drug discovery, as well as for monitoring drug delivery and the response of targeted processes to the therapy is a growing trend. A nice (and short) review highlighting the processes, opportunities, and challenges of medical imaging in new drug development is: Medical imaging in new drug clinical development.

The following is dedicated to the role of imaging in guiding treatment.

Precise treatment is a major pillar of modern medicine. An important aspect to enable accurate administration of treatment is complementing the accurate identification of the organ location that needs to be treated with a system and methods that ensure application of treatment only, or mainly to, that location. Imaging is off-course, a major component in such composite systems. Amongst the available solution, functional-imaging modalities are gaining traction. Specifically, molecular imaging (e.g. PET, MRS) allows the visual representation, characterization, and quantification of biological processes at the cellular and subcellular levels within intact living organisms. In oncology, it can be used to depict the abnormal molecules as well as the aberrant interactions of altered molecules on which cancers depend. Being able to detect such fundamental finger-prints of cancer is key to improved matching between drugs-based treatment and disease. Moreover, imaging-based quantified monitoring of changes in tumor metabolism and its microenvironment could provide real-time non-invasive tool to predict the evolution and progression of primary tumors, as well as the development of tumor metastases.

A recent review-paper: Image-guided interventional therapy for cancer with radiotherapeutic nanoparticles nicely illustrates the role of imaging in treatment guidance through a comprehensive discussion of; Image-guided radiotherapeutic using intravenous nanoparticles for the delivery of localized radiation to solid cancer tumors.

 Graphical abstract

 Abstract

One of the major limitations of current cancer therapy is the inability to deliver tumoricidal agents throughout the entire tumor mass using traditional intravenous administration. Nanoparticles carrying beta-emitting therapeutic radionuclides [DN: radioactive isotops that emits electrons as part of the decay process a list of β-emitting radionuclides used in radiotherapeutic nanoparticle preparation is given in table1 of this paper.) that are delivered using advanced image-guidance have significant potential to improve solid tumor therapy. The use of image-guidance in combination with nanoparticle carriers can improve the delivery of localized radiation to tumors. Nanoparticles labeled with certain beta-emitting radionuclides are intrinsically theranostic agents that can provide information regarding distribution and regional dosimetry within the tumor and the body. Image-guided thermal therapy results in increased uptake of intravenous nanoparticles within tumors, improving therapy. In addition, nanoparticles are ideal carriers for direct intratumoral infusion of beta-emitting radionuclides by convection enhanced delivery, permitting the delivery of localized therapeutic radiation without the requirement of the radionuclide exiting from the nanoparticle. With this approach, very high doses of radiation can be delivered to solid tumors while sparing normal organs. Recent technological developments in image-guidance, convection enhanced delivery and newly developed nanoparticles carrying beta-emitting radionuclides will be reviewed. Examples will be shown describing how this new approach has promise for the treatment of brain, head and neck, and other types of solid tumors.

The challenges this review discusses

  • intravenously administered drugs are inhibited in their intratumoral penetration by high interstitial pressures which prevent diffusion of drugs from the blood circulation into the tumor tissue [1–5].
  • relatively rapid clearance of intravenously administered drugs from the blood circulation by kidneys and liver.
  • drugs that do reach the solid tumor by diffusion are inhomogeneously distributed at the micro-scale – This cannot be overcome by simply administering larger systemic doses as toxicity to normal organs is generally the dose limiting factor.
  • even nanoparticulate drugs have poor penetration from the vascular compartment into the tumor and the nanoparticles that do penetrate are most often heterogeneously distributed

How imaging could mitigate the above mentioned challenges

  • The inclusion of an imaging probe during drug development can aid in determining the clearance kinetics and tissue distribution of the drug non-invasively. Such probe can also be used to determine the likelihood of the drug reaching the tumor and to what extent.

Note: Drugs that have increased accumulation within the targeted site are likely to be more effective as compared with others. In that respect, Nanoparticle-based drugs have an additional advantage over free drugs with their potential to be multifunctional carriers capable of carrying both therapeutic and diagnostic imaging probes (theranostic) in the same nanocarrier. These multifunctional nanoparticles can serve as theranostic agents and facilitate personalized treatment planning.

  • Imaging can also be used for localization of the tumor to improve the placement of a catheter or external device within tumors to cause cell death through thermal ablation or oxidative stress secondary to reactive oxygen species.

See the example of Vintfolide in The Role of Medical Imaging in Personalized Medicine

vinta

Note: Image guided thermal ablation methods include radiofrequency (RF) ablation, microwave ablation or high intensity focused ultrasound (HIFU). Photodynamic therapy methods using external light devices to activate photosensitizing agents can also be used to treat superficial tumors or deeper tumors when used with endoscopic catheters.

  • Quality control during and post treatment

For example: The use of high intensity focused ultrasound (HIFU) combined with nanoparticle therapeutics: HIFU is applied to improve drug delivery and to trigger drug release from nanoparticles. Gas-bubbles are playing the role of the drug’s nano-carrier. These are used both to increase the drug transport into the cell and as ultrasound-imaging contrast material. The ultrasound is also used for processes of drug-release and ablation.

 HIFU

Additional example; Multifunctional nanoparticles for tracking CED (convection enhanced delivery)  distribution within tumors: Nanoparticle that could serve as a carrier not only for the therapeutic radionuclides but simultaneously also for a therapeutic drug and 4 different types of imaging contrast agents including an MRI contrast agent, PET and SPECT nuclear diagnostic imaging agents and optical contrast agents as shown below. The ability to perform multiple types of imaging on the same nanoparticles will allow studies investigating the distribution and retention of nanoparticles initially in vivo using non-invasive imaging and later at the histological level using optical imaging.

 multi

Conclusions

Image-guided radiotherapeutic nanoparticles have significant potential for solid tumor cancer therapy. The current success of this therapy in animals is most likely due to the improved accumulation, retention and dispersion of nanoparticles within solid tumor following image-guided therapies as well as the micro-field of the β-particle which reduces the requirement of perfectly homogeneous tumor coverage. It is also possible that the intratumoral distribution of nanoparticles may benefit from their uptake by intratumoral macrophages although more research is required to determine the importance of this aspect of intratumoral radionuclide nanoparticle therapy. This new approach to cancer therapy is a fertile ground for many new technological developments as well as for new understandings in the basic biology of cancer therapy. The clinical success of this approach will depend on progress in many areas of interdisciplinary research including imaging technology, nanoparticle technology, computer and robot assisted image-guided application of therapies, radiation physics and oncology. Close collaboration of a wide variety of scientists and physicians including chemists, nanotechnologists, drug delivery experts, radiation physicists, robotics and software experts, toxicologists, surgeons, imaging physicians, and oncologists will best facilitate the implementation of this novel approach to the treatment of cancer in the clinical environment. Image-guided nanoparticle therapies including those with β-emission radionuclide nanoparticles have excellent promise to significantly impact clinical cancer therapy and advance the field of drug delivery.

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Reporter and Curator: Dr. Sudipta Saha, Ph.D.

The prostate has long been known to exhibit unique metabolite profiles. In the last decade, advances in nuclear magnetic resonance spectroscopy and mass spectrometry have been applied toward identifying metabolic alterations in prostate cancer that may provide clinically useful biomarkers. As with genomics and proteomics, advances in technology and bioinformatics have led to the application of metabolomic profiling to prostate cancer—the high throughput evaluation of a large complement of metabolites in the prostate and how they are altered by disease perturbations. Recently, high profile publications have drawn attention to the potential of metabolomic analysis to identify biomarkers for early detection or disease progression from readily accessible body fluids as well as tissue specimens from biopsy and surgery.

Worldwide, the number of prostate cancer cases is approaching one million, and it is the sixth leading cause of cancer deaths in men. Both incidence and mortality are increasing in many traditionally low risk countries in Asia, and Central and Eastern Europe. Testing with serum prostate specific antigen has contributed to decreases in prostate cancer mortality in many developed countries, but the test and the diagnostic paradigm suffer from a number of problems, including low specificity of prostate specific antigen, inability to specify a cut-point below which cancer is unlikely, non-trivial false-negative rate for prostate biopsy, and over-diagnosis and over-treatment of relatively indolent tumors with low potential for morbidity or death if left untreated. For men diagnosed with prostate cancer, a number of algorithms primarily based on tumor pathology and prostate specific antigen are available to predict the likely clinical outcome. Although these prediction tools generally work well, there is still significant variability in outcomes for men at both the low and high end of the risk spectrum. Although distinct metabolic characteristics of the prostate have long been known, global metabolomic profiling of prostate cancer is at an early stage.

Studies of the metabolic alterations associated with prostate cancer have demonstrated characteristic decreases in citrate and polyamines, and increases in cholines, glycerophospholipids, lactate, and components of a number of pathways of amino acid metabolism. Results for sarcosine have been prominent but inconsistent. However, it is likely that inconsistent findings are not unique to sarcosine. Rather, the attention given to sarcosine has resulted in reports of validation efforts focused on this molecule, whereas reports from other metabolomic profiling studies have focused on discovery and have not emphasized null associations. Metabolite profiles with potential relevance to prostate cancer biology have been identified in tissue, bone, urine, expressed prostatic fluid, and plasma, and have correlated with clinical progression as well as established prognostic attributes. Given the relatively low cost of metabolomic profiling compared with the other ‘omics’ disciplines, and the parallel advances being made in molecular magnetic resonance imaging, metabolomics has great potential for application to detection of clinically significant disease and monitoring disease progression, in both the active surveillance and post-treatment settings. In addition, because of their functional significance, metabolomic biomarkers or profiles hold particular promise for addressing one of the current challenges to personalized medicine: co-development of targeted therapeutics and companion diagnostics.

Source References:

http://www.ncbi.nlm.nih.gov/pubmed/21930089

http://people.ucalgary.ca/~adeleon/paper_prostate.pdf

http://www.ctsi.ufl.edu/wp-content/uploads/2012/06/DeFeo-2011-A-decade-in-prostate.pdf

http://www.fasebj.org/cgi/content/meeting_abstract/21/6/A768-c

http://onlinelibrary.wiley.com/doi/10.1002/pros.22704/abstract

http://dept.stat.lsa.umich.edu/~gmichail/journal.pone.0021417.pdf

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In Search of Clarity on Prostate Cancer Screening, Post-Surgical Followup, and Prediction of Long Term Remission

Larry H. Bernstein, MD, FCAP, Author and Curator
Dror Nir, PhD, Curator
Aviva Lec-Ari, PhD, RN, Curator

There have been two important articles in the last several days giving perspectives on the current and evolving status of current and evolving diagnosis of prostate cancer (PCA) by experts Dror Nir, PhD and Aviva Lev-Ari, PhD, RN, Editor-in-Chief, http://Pharmaceuticalintelligence.com

The first article reviews the recent published update on PCA screening and diagnosis, as determined by review of the literature by an Expert Panel, in order to determine what is the current validated Evidence-Based Medicine Practice Guideline for American Urological Surgeons.

The method of review is rigorously laid out and follows the accepted standard for publication.  The emphasis in the study lies in the reliance on prostate specific abtigen (PSA), which has undergone an evolutioary improvement sine 1999, although substantiation of a benefit could not be trusted until almost a decade later.   The problem the is notable is the absence of discussion of improvements in cancer imaging that has also evolved in that time period, and continues to evolve with molecular probes.

Early Detection of Prostate Cancer: American Urological Association (AUA) Guideline

Author-Writer: Dror Nir, PhD

https://pharmaceuticalintelligence.com/2013/05/21/early-detection-of-prostate-cancer-aua-guideline/

When reviewing the DETECTION OF PROSTATE CANCER section on the AUA website , The first thing that catches one’s attention is the image below; clearly showing two “guys” exploring with interest what could be a CT or MRI image….

But, if you bother to read the review underneath this image regarding EARLY DETECTION OF PROSTATE CANCER: AUA GUIDELINE produced by an independent group that was commissioned by the AUA to conduct a systematic review and meta-analysis of the published literature on prostate cancer detection and screening; Panel Members: H. Ballentine Carter, Peter C. Albertsen, Michael J. Barry, Ruth Etzioni, Stephen J. Freedland, Kirsten Lynn Greene, Lars Holmberg, Philip Kantoff, Badrinath R. Konety, Mohammad Hassan Murad, David F. Penson and Anthony L. Zietman – You are bound to be left with a strong feeling that something is wrong!

“The AUA commissioned an independent group to conduct a systematic review and meta-analysis of the published literature on prostate cancer detection and screening. The protocol of the systematic review was developed a priori by the expert panel. The search strategy was developed and executed by reference librarians and methodologists and spanned across multiple databases including Ovid Medline In-Process & Other Non-Indexed Citations, Ovid MEDLINE, Ovid EMBASE, Ovid Cochrane Database of Systematic Reviews, Ovid Cochrane Central Register of Controlled Trials and Scopus. Controlled vocabulary supplemented with keywords was used to search for the relevant concepts of prostate cancer, screening and detection. The search focused on DRE, serum biomarkers (PSA, PSA Isoforms, PSA kinetics, free PSA, complexed PSA, proPSA, prostate health index, PSA velocity, PSA doubling time), urine biomarkers (PCA3, TMPRSS2:ERG fusion), imaging (TRUS, MRI, MRS, MR-TRUS fusion), genetics (SNPs), shared-decision making and prostate biopsy. The expert panel manually identified additional references that met the same search criteria”

While reading through the document, I was looking for the findings related to the roll of imaging in prostate cancer screening; see highlighted above. The only thing I found: “With the exception of prostate-specific antigen (PSA)-based prostate cancer screening, there was minimal evidence to assess the outcomes of interest for other tests.”

This must mean that: Notwithstanding hundreds of men-years and tens of millions of dollars which were invested in studies aiming to assess the contribution of imaging to prostate cancer management, no convincing evidence to include imaging in the screening progress was found by a group of top-experts in a thorough and rigorously managed literature survey! And it actually  lead the AUA to declare that “Nothing new in the last 20 years”…..

My interpretation of this: It says-it-all on the quality of the clinical studies that were conducted during these years, aiming to develop an improved prostate cancer workflow based on imaging. I hope that whoever reads this post will agree that this is a point worth considering!

For those who do not want to bother reading the whole AUA guidelines document here is a peer reviewed summary:

“Early Detection of Prostate Cancer: AUA Guideline; Carter HB, Albertsen PC, Barry MJ, Etzioni R, Freedland SJ, Greene KL, Holmberg L, Kantoff P, Konety BR, Murad MH, Penson DF, Zietman AL; Journal of Urology (May 2013)”

It says:

“A systematic review was conducted and summarized evidence derived from over 300 studies that addressed the predefined outcomes of interest (prostate cancer incidence/mortality, quality of life, diagnostic accuracy and harms of testing). In addition to the quality of evidence, the panel considered values and preferences expressed in a clinical setting (patient-physician dyad) rather than having a public health perspective. Guideline statements were organized by age group in years (age<40; 40 to 54; 55 to 69; ≥70).

RESULTS: With the exception of prostate-specific antigen (PSA)-based prostate cancer screening, there was minimal evidence to assess the outcomes of interest for other tests. The quality of evidence for the benefits of screening was moderate, and evidence for harm was high for men age 55 to 69 years. For men outside this age range, evidence was lacking for benefit, but the harms of screening, including over diagnosis and over treatment, remained. Modeled data suggested that a screening interval of two years or more may be preferred to reduce the harms of screening.

Prostate Cancer Molecular Diagnostic Market – the Players are: SRI Int’l, Genomic Health w/Cleveland Clinic, Myriad Genetics w/UCSF, GenomeDx and BioTheranostics

Curator: Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2013/05/21/prostate-cancer-molecular-diagnostic-market-the-players-are-sri-intl-genomic-health-wcleveland-clinic-myriad-genetics-wucsf-genomedx-and-biotheranostics/

On February 6, 2013 we reported that DR. MARK RUBIN, LEADING PROSTATE CANCER AND GENOMICS EXPERT, TO LEAD CUTTING-EDGE CENTER FOR TARGETED, INDIVIDUALIZED PATIENT CARE BASED ON EACH PATIENT’S GENETICS

Genomically Guided Treatment after CLIA Approval: to be offered by Weill Cornell Precision Medicine Institute

On May 16, 2013 we reported a major breakthrough in the Prostate Cancer Screening

A Blood Test to Identify Aggressive Prostate Cancer: a Discovery @ SRI International, Menlo Park, CA

After nearly a decade, my collaborators and I have found the first marker that specifically identifies the approximately six to eight percent of prostate cancers that are considered “aggressive,” meaning they will migrate to other parts of the body, at which point they are very difficult to treat. Although we have confirmed this marker, there is much to be done before a clinical application can be developed.

https://pharmaceuticalintelligence.com/2013/05/16/a-blood-test-to-identify-aggressive-prostate-cancer-a-discovery-sri-international-menlo-park-ca/

Prostate Cancer MDx Competition Heating Up; New Data from Genomic Health, Myriad

May 15, 2013  By Turna Ray

Life sciences companies are gearing up for battle to capture the profitable prostate cancer molecular diagnostic market.

Genomic Health and Myriad Genetics both made presentations to the investment community last week about their genomic tests that gauge a man’s risk of prostate cancer aggressiveness. As part of its annual investor day, Myriad discussed new data on its Prolaris test, which analyzes the expression level of 46 cell cycle progression genes and stratifies men’s risk of biochemical recurrence of prostate cancer. If the test reports low gene expression, then the patient is at low risk of disease progression, while high gene expression is associated with disease progression.

Meanwhile, around the same time last week, Genomic Health launched its Oncotype DX prostate cancer test and presented data from the first validation study involving the diagnostic. The Oncotype DX prostate cancer test analyzes the expression of 17 genes within four biological pathways to gauge prostate cancer aggressiveness. The test reports a genomic prostate score from 0 to 100; the lower the score the more certain a patient can be that they can avoid treatment and continue with active surveillance. Prostate cancer patients who are deemed to be at very low risk, low risk, or intermediate risk of progressing are eligible to be tested with the Oncotype Dx test. If, based on standard clinical measures, a person’s prostate cancer is considered high risk, then he is not a candidate for Genomic Health’s test.

These molecular tests are entering the market at a time when currently available tools aren’t specific enough to distinguish between men who have an aggressive form of prostate cancer and therefore, need invasive treatments, and those that are low risk and can do well with active surveillance. According to an NIH estimate, in 2010, the annual medical costs associated with prostate cancer in the US were $12 billion.

It is estimated that each year 23 million men undergo testing for prostate specific antigen, a protein produced by the prostate gland that increases when a man has prostate cancer. Additionally, one million men get a prostate biopsy annually, while 240,000 men end up with a diagnosis for prostate cancer, and around 30,000 die from the disease. Although most of the men diagnosed with prostate cancer end up receiving surgery or radiation treatment, as many as half of these men will probably not progress, and their disease isn’t life threatening.

While PSA testing has been shown to reduce prostate cancer deaths, a man’s PSA level may be increased for reasons other than cancer. As such, broadly screening men for PSA has been controversial in the healthcare community since the test isn’t specific enough to gauge which men are at low risk of developing aggressive prostate cancer and can forgo unnecessary treatments that can have significant side effects.

Both Myriad and Genomic Health are hoping their tests will further refine prostate cancer diagnosis and help doctors gain more confidence in determining which of their patients have aggressive disease and which are at low risk.

Myriad’s advantage

In this highly competitive space, Myriad has the first mover advantage, having launched Prolaris three years ago. The company has published four studies involving the test and conducted a number of trials analyzing around 3,000 patient samples.

Researchers from UCSF and Myriad recently published the fourth validation study in the Journal of Clinical Oncology, which analyzed samples from 400 men who had undergone a radical prostatectomy. In the published study, researchers reported that 100 percent of the men whom Prolaris deemed to be at “low risk” of progression did not experience a recurrence within the five years the study was ongoing. Meanwhile, 50 percent of those the test deemed to be a “high risk” did experience recurrence during that time (PGx Reporter 3/6/2013).

New competition

Like Myriad’s BRACAnalysis test, which comprises more than 80 percent of its product revenues, Genomic Health’s Oncotype DX breast cancer recurrence tests is bringing in the majority of its product revenues. However, the company believes that its newly launched Oncotype DX prostate cancer test stands to be its largest market opportunity to date.

Last week, researchers from University of California, San Francisco, presented data from the first validation study involving the Oncotype DX prostate cancer test. The study involved nearly 400 prostate cancer patients considered low or intermediate risk by standard methods such as Gleason score and showed that when the Oncotype DX score was used in conjunction with other measures, investigators identified more patients as having very low risk disease who were appropriate for active surveillance than when they diagnosed patients without the test score.

More than one third of patients classified as low risk by standard measures in the study were deemed to be “very low risk” by Oncotype DX and therefore could choose active surveillance. Meanwhile, 10 percent of patients in the study were found by clinical measures to be at very low risk or low risk, but the Oncotype DX test deemed them as having aggressive disease that needed treatment.

Matthew Cooperberg of UCSF, who presented data from this validation study at the American Urological Association’s annual meeting last week, highlighted this feature of the Oncotype DX prostate cancer test to investors during a conference call last week. He noted that the test not only gauges which low-risk patients can confidently remain with active surveillance, but it also finds those patients who didn’t receive an accurate risk assessment based on standard clinical measures. “It’s also equally important that we identify the man who frankly should not be on active surveillance, because they’re out there,” he said.

Genomic Health has aligned its test with guidelines from the National Comprehensive Cancer Network, which has expressed concern about over-diagnosis and over-treatment in prostate cancer patients. In 2010, NCCN guidelines established a new “very low risk” category for men with clinically insignificant prostate cancer and recommended that men who fall into this category and have a life expectancy of more than 20 years should only be followed with active surveillance. In 2011, NCCN made the active surveillance criteria more stringent for men in the “very low risk” category.

In order to develop the prostate cancer test, Genomic Health collaborated with the Cleveland Clinic on six feasibility studies and selected the gene expression panel after analyzing 700 genes on tissue samples from 700 patients. The commercial test analyzes the expression of 17 genes across four biological

I am quite surprised that nothing is said about the current status of  PSA for Pca, which is far advanced today, and it also needs attention.  We are in the old SUFI tale about the blind men who grasped the trunk, or the tail, etc., and called it the elephant.

Robustness of ProsVue™ linear slope for prognostic identification of patients at reduced risk for prostate cancer recurrence: Simulation studies on effects of analytical imprecision and sampling time variation

Mark J. Sarno, Charles S. Davis
Clinical Biochemistry  Nov 2012;  45 (16–17): 1479-1484
Highlights
► We simulate effects of analytical and sampling time variation on ProsVue slope.
 ► Classification switching is minimal in both stable disease and recurrence.
 ► We provide a framework for assessment of assays using rate of change principles
Objective
The ProsVue assay measures serum total prostate-specific antigen (PSA) over three time points post-radical prostatectomy and calculates rate of change expressed as linear slope. Slopes ≤ 2.0 pg/ml/month are associated with reduced risk for prostate cancer recurrence. However, an indicator based on measurement at multiple time points, calculation of slope, and relation of slope to a binary cutoff may be subject to effects of analytical imprecision and sampling time variation. We performed simulation studies to determine the presence and magnitude of such effects.
Design and methods
Using data from a two-site precision study and a multicenter clinical trial of 304 men, we performed simulation studies to assess whether analytical imprecision and sampling time variation can drive misclassifications or classification switching of patients with stable disease or recurrence.
Results
Analytical imprecision related to expected PSA values in a stable disease population results in ≤ 1.2% misclassifications. For populations with recurrent disease, an analysis taking into account correlation between sampling time points demonstrates that classification switching across the 2.0 pg/ml/month cutoff occurs at a rate ≤ 11%. In the narrow region of overlap between populations, classification switching maximizes at 12.3%. Lastly, sampling time variation across a wide range of scenarios results in 99.7% retention of proper classification for stable disease patients with linear slopes up to the 75th percentile of the distribution.
Conclusions
These results demonstrate the robustness of the ProsVue assay and the linear slope indicator. Further, these simulation studies provide a potential framework for evaluation of future assays that rely on the rate of change principle.
As the reviewer of this paper for Clinical Biochemistry, I have never encountered such a beautiful and rigorous evaluation that is described in the outline below:
Article Outline
1. Introduction
2. Materials and Methods
2.1. Source data
2.2. Simulation 1 – Effects of analytical imprecision in patients with stable disease
2.3. Simulations 2 and 3 – Effects of analytical imprecision in patients with PCa recurrence
2.4. Simulations 4 and 5 – Simulations in highest tertile of stable disease slopes and lowest tertile of recurrent slopes
2.5. Simulation 6 – Effects of sampling time variation
2.6. Software
3. Results
3.1. Source data for simulations
3.2. Simulation 1 – Effects of analytical imprecision in patients with stable disease
3.3. Simulations 2 and 3 – Effects of analytical imprecision in patients with PCa recurrence
3.4. Simulations 4 and 5 — Simulations in highest tertile of stable disease slopes and lowest tertile of recurrent slopes
3.5. Simulation 6 – Effects of sampling time variation
4. Discussion
5. Conclusions
References

This article is followed by another in the Urology journal.

NADiA ProsVue prostate-specific antigen slope is an independent prognostic marker for identifying men at reduced risk of clinical recurrence of prostate cancer after radical prostatectomy.

Moul JW, Lilja H, Semmes OJ, Lance RS, Vessella RL, Fleisher M, Mazzola C, Sarno MJ, Stevens B, Klem RE, McDermed JE, Triebell MT, Adams TH.
Division of Urologic Surgery and Duke Cancer Institute, Duke University Medical Center, Durham, North Carolina 27710, USA. judd.moul@duke.edu
Urology. 2012 Dec;80(6):1319-25. http://dx.doi.org/10.1016/j.urology.2012.06.080. Epub 2012 Oct 26.
OBJECTIVE:
To validate the hypothesis that men displaying serum prostate-specific antigen (PSA) slopes ≤ 2.0 pg/mL/mo after prostatectomy, measured using a new immuno-polymerase chain reaction diagnostic test (NADiA ProsVue), have a reduced risk of clinical recurrence as determined by positive biopsy, imaging findings, or death from prostate cancer.
MATERIALS AND METHODS:
From 4 clinical sites, we selected a cohort of 304 men who had been followed up for 17.6 years after prostatectomy for clinical recurrence. We assessed the prognostic value of a PSA slope cutpoint of 2.0 pg/mL/mo against established risk factors to identify men at low risk of clinical recurrence using uni- and multivariate Cox proportional hazards regression and Kaplan-Meier analyses.
RESULTS:
The univariate hazard ratio of a PSA slope >2.0 pg/mL/mo was 18.3 (95% confidence interval 10.6-31.8) compared with a slope ≤ 2.0 pg/mL/mo (P <.0001). The median disease-free survival interval was 4.8 years vs >10 years in the 2 groups (P <.0001). The multivariate hazard ratio for PSA slope with the covariates of preprostatectomy PSA, pathologic stage, and Gleason score was 9.8 (95% confidence interval 5.4-17.8), an 89.8% risk reduction for men with PSA slopes ≤ 2.0 pg/mL/mo (P <.0001). The Gleason score (<7 vs ≥ 7) was the only other significant predictor (hazard ratio 5.4, 95% confidence interval 2.1-13.8, P = .0004).
CONCLUSION:
Clinical recurrence after radical prostatectomy is difficult to predict using established risk factors. We have demonstrated that a NADiA ProsVue PSA slope of ≤ 2.0 pg/mL/mo after prostatectomy is prognostic for a reduced risk of prostate cancer recurrence and adds predictive power to the established risk factors.
Urology. 2012 Dec;80(6):1325-6; author reply 1326-7. http://dx.doi.org/10.1016/j.urology.2012.06.081. Epub 2012 Oct 26.      Collins S.
Editorial comment.
NADiA ProsVue prostate-specific antigen slope is an independent prognostic marker for identifying men at reduced risk of clinical recurrence of prostate cancer after radical prostatectomy. [Urology. 2012]

Why NADiA ProsVue?      IRIS INTERNATIONAL

Some patients who had surgery to remove the prostate may be at higher risk for recurrence. Determining the risk of recurrence is critical for these patients and their physicians in order to make the most informed decision possible about future medical management.
Physicians use post-surgical risk assessment to review a variety of parameters to help determine if the patient might develop recurrent disease.  Risk factors may include:
  • The size and proximity of the tumor at the time of surgery (whether it has grown through the prostate walls):
Through imaging tests, physicians can determine how far cancerous tissue may have spread, with indicators such as
  • extracapsular extensions (ECE, beyond the prostatic capsule) and
  • seminal vesicle invasion (SVI, presence in the walls of the vesicles surrounding the prostate).
  • The presence of cancer cells at the edge of the removed tumor (known as positive margins) or in the lymph nodes outside the prostate.
  • A high preoperative PSA level (> 20 ng/mL).
  • The tumor’s Gleason Score (if it is at least 8 or higher).
However, current risk assessment relies on subjective and imprecise information. This uncertainty can have a dramatic impact on a patient’s personal experience after prostatectomy.
The newly available NADiA ProsVue test may help provide a more clear and accurate prediction of a patient’s true risk for clinical recurrence.
The NADiA ProsVue test measures
  • the rate of change of PSA at extremely low levels over time, which can help quickly and accurately identify patients
  • who are at reduced risk for clinical recurrence.

In conjunction with other information, NADiA ProsVue may allow some men to avoid unnecessary treatments and anxiety after prostatectomy.

NADiA ProsVue is an in-vitro diagnostic assay for determining
  • rate of change of serum total prostate specific antigen (tPSA) over a period of time (slope, pg/mL per month).
The NADiA ProsVue assay is performed for patients having less than 0.1 ng/mL serum tPSA values (determined by standard-of-care assays that are FDA approved/cleared) in the first sample collected more than 6 weeks after radical prostatectomy.

What is NADiA?

NADiA stands for Nucleic Acid Detection immunoassay.  Immuno-PCR, first described by Sano and Cantor in 1992 involves combining protein antigen detection by immunoassay with the detection sensitivity and precision of real-time polymerase chain reaction (qPCR).  This amplified DNA-immunoassay approach is similar to that of an enzyme immunoassay, involving antibody binding reactions and intermediate washing steps.  The enzyme label is replaced by a strand of DNA and detected by exponential amplification using qPCR.

NADiA employs a soluble (reporter) monoclonal antibody (MAb) labeled with an assay-specific double-stranded DNA sequence.

  • The presence of this DNA label does not interfere with MAb binding, nor
  • does the MAb interfere with DNA label amplification and detection.
  • The second (capturing) MAb specific for another site on the target protein (antigen)
    is coated onto paramagnetic microparticles.

The reporter MAb-DNA conjugate is reacted with sample in a microtiter plate format to form a first immune complex with the target antigen. The immune complex is then captured onto paramagnetic particles coated with the second capture MAb, forming an insoluble sandwich immune complex. The microparticles are washed by several cycles of magnetic capture and re-suspension to remove excess reporter MAb-DNA conjugate.
The specifically bound DNA label is then detected by subjecting

  • suspended particles to qPCR conditions and monitoring the generations of amplicon in real time.


What are possible clinical applications?

Proteins play a crucial role in all biological functions. Identifying and measuring the quantity of specific proteins is fundamental to understanding the cause and evolution of many human disease processes.
There are hundreds of thousands of proteins in the human body, but the vast majority are present at extremely low concentrations. For example, only ten (10) proteins make up 90% of the mass of plasma proteins found in human serum. Twelve (12) proteins make up another 9% of the mass. The remaining proteins comprise the final 1%. Advancing medicine through the study of proteins (known as proteomics) requires powerful and sensitive tools.
http://www.irispermed.com/images/pictures/Protein_Slide_2.png

NADiA combines the specificity of an immunoassay with the detection sensitivity of qPCR and can assist efforts to provide clinical insight into many human diseases.  Any disease process involving proteins below the detection limits of today’s enzyme immunoassays (EIA) is a potential target for NADiA.
NADiA ProsVue is the first of a line of assays designed to advance human healthcare in the areas of oncology and infectious disease.

510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION

DECISION SUMMARY
A. 510(k) Number:
k101185
B. Purpose for Submission:
New device
C. Measurand:
Total Prostate specific antigen (tPSA)
D. Type of Test:
Quantitative, Immuno-PCR (Polymerase Chain Reaction)
E. Applicant:
Iris Molecular Diagnostics
F. Proprietary and Established Names:
NADiA® ProsVue™

 Intended Use:

NADiA® ProsVue™ is an in-vitro diagnostic assay for determining rate of change of serum total prostate specific antigen over a period of time (slope, pg/mL per month). The NADiA® ProsVue™ assay is performed for patients having less than 0.1 ng/mL serum total PSA values (determined by standard-of-care assays that are FDA approved/cleared) in the first sample collected more than 6 weeks after radical prostatectomy. ProsVue™ slope is indicated for use as a prognostic marker in conjunction with clinical evaluation as an aid in identifying those patients at reduced risk for recurrence of prostate cancer for the eight year period following prostatectomy.
The NADiA® ProsVue™ assay is not intended for the diagnosis or for the monitoring of prostate cancer.
 †”Recurrence” is defined as clinical recurrence, not biochemical recurrence, and was documented by positive imaging, positive biopsy, or death due to prostate cancer.

U.S. FDA approves NADiA ProsVue prognostic test for prostate cancer

Posted on September 23, 2011 by Sitemaster

According to a media release issued

Moul et al. have now conducted a retrospective, multi-center clinical trial to further evaluate the potential prognostic value of ProsVue slope at a decision threshold of 2 pg/ml/month. (One nanogram or 1 ng = 1,000 picograms or 1,000 pg.)
The retrospective analysis was based on data from 392 prostate cancer patients who had been given radical prostatectomies between November 1991 and August 2001. To be eligible for this study, all of the following data had to be available from individual patients:
  1. A first post-surgical PSA level of <100 pg/ml (i.e., <  0.1 ng/ml)
  2. Full pathologic and radiographic data
  3. Three frozen serum samples drawn between 6 weeks and 19.4 months post-surgery.
  4. Patients were not eligible if they had received adjuvant radiotherapy and/or hormone therapy after surgery and prior to completion of the three post-surgical blood draws.
The results of this retrospective study showed that:
  1. The average (median) PSA levels of the 392 patients was 6.3 ng/ml (range, 0 to 60.6 ng/ml)
  2. The average (median) post-surgical Gleason score was 7.0 (range, 4 to 10).
73 patients had received neoadjuvant hormone therapy prior to their surgery.
The pathologic stages of the patients were
pT0-2, n = 228
pT3, n = 147
pT4, n = 17
116 patients had positive margins and 8 had positive lymph nodes.
The three post-surgical PSA values were based on serum drawn
  • after median times of 4.9, 8.6, and 12.8 months and showed median values of 10.7, 23.0 and 50.7 pg/ml, respectively.
The sensitivity, specificity, PPV and NPV for a 2 pg/mL/month ProsVue slope were 75.0, 96.6, 81.4, and 95.2, respectively.
  • At a median follow-up of 10.5 years, 14 patients had died of prostate cancer and 40 had died overall.
The authors conclude the the ProsVue test “provides information previously unknown” in patients in the first year post-surgery, and that a ProsVue slope of  ≤ 2 pg/mL/month in that first year is highly associated with a lack of evidence of progression in long-term follow-up.
In theory, the ProsVue test may have some clinical value in the identification of patients who do not need long-term oncologic follow-up and in predicting the need for adjuvant radiation therapy. However, additional prospective studies will be necessary before this can be confirmed, and the practical clinical value of such a test would depend on whether it is significantly more accurate that data currently available from ultrasensitive PSA testing.
Additional information is available in a media release from the developer of the ProsVue test (IRIS International). According to that media release, the developer has submitted data to the FDA requesting approval to market this test.
The centers involved in this study included Duke University, Memorial Sloan-Kettering Cancer Center, Eastern Virginia Medical Center, and the University of Washington — all of which are highly reputable institutions.
NADiA ProsVue results are calculated as the linear slope of three NADiA ProsVue total PSA test results obtained on three serum samples collected between six weeks and 20 months post-radical prostatectomy.

by IRIS International, the U.S. Food & Drug Administration (FDA) has approved the company’s NADiA® ProsVue™ test as a prognostic marker that can “aid in identifying” men at reduced risk for recurrence of prostate cancer in the first 8 years after a prostatectomy

NADiA ProsVue: A prognostic test for identifying men at a reduced risk for prostate cancer recurrence following radical prostatectomy

J. Moul2, R. Lance1, J. Alter3, M. Sarno3, J. McDermed3
1 Eastern Virginia Medical School, Norfolk, USA
2 Duke Prostate Center, Durham, USA
3 Iris Molecular Diagnostics, Carlsbad, USA

Introduction: Clinical recurrence after radical prostatectomy (RP) is difficult to predict since established factors do not reliably stratify risk. We validated a pre-specified hypothesis that a post-RP NADiA® PSA slope cutpoint of ≤2.0 pg/mL/month (mo) identifies men at reduced risk of clinical recurrence as determined by positive biopsy, imaging or prostate cancer death. This study aimed to compare the prognostic strength of the ProsVue slope cutpoint vs. surgical margin status to identify men at very low risk of post-RP clinical recurrence.
Methods: From a cohort of 304 men, surgical margin data was available for 234 men. PSA was measured with a Nucleic Acid Detection Immunoassay (NADiA®) having a limit of quantification of 0.00065 ng (0.65 pg) per mL. Least-squares linear PSA slope (ProsVue™) was calculated using 3 serum samples drawn 1.5-20 mo post-RP. Recurrence risk using a 2.0 pg/mL/mo ProsVue cutpoint and surgical margin status were compared by two survival methods, univariate Cox proportional hazards regression analysis (table) and Kaplan-Meier plots (figure).
Results: ProsVue slope ≤2.0 pg/mL/mo was significantly associated with a reduced risk of clinical recurrence by univariate Cox analysis (HR 18.3, 95% CI, 10.6–31.8, P < 0.0001). A negative surgical margin was less significantly associated with a reduced risk of recurrence (HR 3.3, 95% CI 2.0–5.4). Median time to recurrence for men with ProsVue slope ≤2.0 pg/mL/mo and those with negative margins exceeded 17.6 years (yrs). However, median time to recurrence in men with ProsVue slope >2.0 pg/mL/mo was shorter compared to those with positive margins.

NADiA ProsVue Prostate-specific Antigen Slope Is an Independent Prognostic Marker for Identifying Men at Reduced Risk of Clinical Recurrence of Prostate Cancer After Radical Prostatectomy

Judd W. Moul, Hans Lilja, O. John Semmes, Raymond S. Lance, Robert L. Vessella, Martin Fleisher, Clarisse Mazzola, Mark J. Sarno, Barbara Stevens, Robert E. Klem, Jonathan E. McDermed, Melissa T. Triebell, Thomas H. Adams
Urology Dec 2012; 80(6): 1319-1327,

Objective
To validate the hypothesis that men displaying serum prostate-specific antigen (PSA) slopes ≤2.0 pg/mL/mo after prostatectomy, measured using a new immuno-polymerase chain reaction diagnostic test (NADiA ProsVue), have a reduced risk of clinical recurrence as determined by positive biopsy, imaging findings, or death from prostate cancer.
Materials and Methods
From 4 clinical sites, we selected a cohort of 304 men who had been followed up for 17.6 years after prostatectomy for clinical recurrence. We assessed the prognostic value of a PSA slope cutpoint of 2.0 pg/mL/mo against established risk factors to identify men at low risk of clinical recurrence using uni- and multivariate Cox proportional hazards regression and Kaplan-Meier analyses.
Results
The univariate hazard ratio of a PSA slope >2.0 pg/mL/mo was 18.3 (95% confidence interval 10.6-31.8) compared with a slope ≤2.0 pg/mL/mo (P <.0001). The median disease-free survival interval was 4.8 years vs >10 years in the 2 groups (P <.0001). The multivariate hazard ratio for PSA slope with the covariates of preprostatectomy PSA, pathologic stage, and Gleason score was 9.8 (95% confidence interval 5.4-17.8), an 89.8% risk reduction for men with PSA slopes ≤2.0 pg/mL/mo (P <.0001). The Gleason score (<7 vs ≥7) was the only other significant predictor (hazard ratio 5.4, 95% confidence interval 2.1-13.8, P = .0004).
Conclusion
Clinical recurrence after radical prostatectomy is difficult to predict using established risk factors. We have demonstrated that a NADiA ProsVue PSA slope of ≤2.0 pg/mL/mo after prostatectomy is prognostic for a reduced risk of prostate cancer recurrence and adds predictive power to the established risk factors.

Fifth–Generation Digital Immunoassay for Prostate Specific Antigen by Single Molecule Array Technology.

D.H. Wilson, D.W. Hanlon, G.K. Provuncher, L. Chang, L. Song, P.P. Patel, E.P. Ferrell, H. Lepor,A.W. Partin, D.W. Chan, L.J. Sokoll, C.D. Cheli, R.P. Thiel, D.R. Fournier, and D.C. Duffy
http://dx.doi.org/10.1373/clinchem.2011.169540

Measurement of prostate specific antigen (PSA) in prostate cancer patients following radical prostatectomy (RP) has been hindered by the limit of quantification of available assays. Because radical prostatectomy removes the tissue responsible for PSA production, postsurgical PSA is typically undetectable with current assay methods. Evidence suggests, however, that more sensitive determination of PSA status following RP could improve assessment of patient prognosis and response to treatment and better target secondary therapy for those who may benefit most. We developed an investigational digital immunoassay with a 2–logs–lower limit of quantification than current ultrasensitive third–generation PSA assays. We developed reagents for a bead–based ELISA for use with high–density arrays of femtolitervolume wells. Anti–PSA capture beads with immunocomplexes and associated enzyme labels were singulated within the wells of the arrays and interrogated for the presence of enzymatic product. We characterized analytical performance, compared its accuracy with a commercially available test, and analyzed longitudinal serum samples from a pilot study of 33 RP patients. The assay exhibited a functional sensitivity (20% interassay CV) <0.05 pg/mL, total imprecision <10% from 1 to 50 pg/mL, and excellent agreement with the comparator method. All RP samples were well within the assay measurement capability. PSA concentrations following surgery were found to be predictive of prostate cancer recurrence risk over 5 years. The robust 2–log improvement in limit of quantification relative to current ultrasensitive assays and the validated analytical performance of the assay allow for accurate assessment of PSA status after RP.

Risk of prostate cancer in two age groups base...

Risk of prostate cancer in two age groups based on Free PSA as % of Total PSA Catalona W, Partin A, Slawin K, Brawer M, Flanigan R, Patel A, Richie J, deKernion J, Walsh P, Scardino P, Lange P, Subong E, Parson R, Gasior G, Loveland K, Southwick P (1998). “Use of the percentage of free prostate-specific antigen to enhance differentiation of prostate cancer from benign prostatic disease: a prospective multicenter clinical trial”. JAMA 279 (19) : 1542–7. doi:10.1001/jama.279.19.1542. PMID 9605898. (Photo credit: Wikipedia)

English: Human prostate specific antigen (PSA/...

English: Human prostate specific antigen (PSA/KLK3) with bound substrate from complex with antibody (PDB id: 2ZCK) (Photo credit: Wikipedia)

Table 1. Side-effects and effects on recovery ...

Table 1. Side-effects and effects on recovery of treatments for newly diagnosed prostate cancer. The Prostate Brachytherapy Advisory Group: http://www.prostatebrachytherapyinfo.net (Photo credit: Wikipedia)

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Curator: Aviva Lev-Ari, PhD, RN

On February 6, 2013 we reported that DR. MARK RUBIN, LEADING PROSTATE CANCER AND GENOMICS EXPERT, TO LEAD CUTTING-EDGE CENTER FOR TARGETED, INDIVIDUALIZED PATIENT CARE BASED ON EACH PATIENT’S GENETICS

Genomically Guided Treatment after CLIA Approval: to be offered by Weill Cornell Precision Medicine Institute

On May 16, 2013 we reported a major breakthrough in the Prostate Cancer Screening

A Blood Test to Identify Aggressive Prostate Cancer: a Discovery @ SRI International, Menlo Park, CA

After nearly a decade, my collaborators and I have found the first marker that specifically identifies the approximately six to eight percent of prostate cancers that are considered “aggressive,” meaning they will migrate to other parts of the body, at which point they are very difficult to treat. Although we have confirmed this marker, there is much to be done before a clinical application can be developed.

https://pharmaceuticalintelligence.com/2013/05/16/a-blood-test-to-identify-aggressive-prostate-cancer-a-discovery-sri-international-menlo-park-ca/

Prostate Cancer MDx Competition Heating Up; New Data from Genomic Health, Myriad

May 15, 2013

Life sciences companies are gearing up for battle to capture the profitable prostate cancer molecular diagnostic market.

Genomic Health and Myriad Genetics both made presentations to the investment community last week about their genomic tests that gauge a man’s risk of prostate cancer aggressiveness. As part of its annual investor day, Myriad discussed new data on its Prolaris test, which analyzes the expression level of 46 cell cycle progression genes and stratifies men’s risk of biochemical recurrence of prostate cancer. If the test reports low gene expression, then the patient is at low risk of disease progression, while high gene expression is associated with disease progression.

Meanwhile, around the same time last week, Genomic Health launched its Oncotype DX prostate cancer test and presented data from the first validation study involving the diagnostic. The Oncotype DX prostate cancer test analyzes the expression of 17 genes within four biological pathways to gauge prostate cancer aggressiveness. The test reports a genomic prostate score from 0 to 100; the lower the score the more certain a patient can be that they can avoid treatment and continue with active surveillance. Prostate cancer patients who are deemed to be at very low risk, low risk, or intermediate risk of progressing are eligible to be tested with the Oncotype Dx test. If, based on standard clinical measures, a person’s prostate cancer is considered high risk, then he is not a candidate for Genomic Health’s test.

These molecular tests are entering the market at a time when currently available tools aren’t specific enough to distinguish between men who have an aggressive form of prostate cancer and therefore, need invasive treatments, and those that are low risk and can do well with active surveillance. According to an NIH estimate, in 2010, the annual medical costs associated with prostate cancer in the US were $12 billion.

It is estimated that each year 23 million men undergo testing for prostate specific antigen, a protein produced by the prostate gland that increases when a man has prostate cancer. Additionally, one million men get a prostate biopsy annually, while 240,000 men end up with a diagnosis for prostate cancer, and around 30,000 die from the disease. Although most of the men diagnosed with prostate cancer end up receiving surgery or radiation treatment, as many as half of these men will probably not progress, and their disease isn’t life threatening.

While PSA testing has been shown to reduce prostate cancer deaths, a man’s PSA level may be increased for reasons other than cancer. As such, broadly screening men for PSA has been controversial in the healthcare community since the test isn’t specific enough to gauge which men are at low risk of developing aggressive prostate cancer and can forgo unnecessary treatments that can have significant side effects.

Both Myriad and Genomic Health are hoping their tests will further refine prostate cancer diagnosis and help doctors gain more confidence in determining which of their patients have aggressive disease and which are at low risk.

Myriad’s advantage

In this highly competitive space, Myriad has the first mover advantage, having launched Prolaris three years ago. The company has published four studies involving the test and conducted a number of trials analyzing around 3,000 patient samples.

Researchers from UCSF and Myriad recently published the fourth validation study in the Journal of Clinical Oncology, which analyzed samples from 400 men who had undergone a radical prostatectomy. In the published study, researchers reported that 100 percent of the men whom Prolaris deemed to be at “low risk” of progression did not experience a recurrence within the five years the study was ongoing. Meanwhile, 50 percent of those the test deemed to be a “high risk” did experience recurrence during that time (PGx Reporter 3/6/2013).

At a major medical conference recently, Myriad presented data from a study which tested biopsy samples from 141 patients treated with electron beam radiation therapy and found that the test score was significantly associated with patients’ outcome and provided information about disease progression beyond standard clinical measures. Although this finding needs to be further validated in a larger patient cohort, the researchers concluded that Prolaris “could be used to select high-risk men undergoing electron beam radiation therapy who may need combination therapy for their clinically localized prostate cancer.” In this study, around half of the cohort was African American.

Myriad has also shown in studies that its test can make accurate predictions from tissue from an initial prostate biopsy and from post-prostatectomy. The test has also shown in studies to be superior to the Gleason score, baseline PSA levels, and other prognostic factors in predicting prostate cancer-specific mortality.

Myriad has nearly completed hiring a 24-person sales force to drive sales of the test. Over the last year, Myriad has received more than 3,000 orders for its Prolaris test and 350 urologists have ordered it. The test carries a $3,400 price tag.

Although the company doesn’t have Medicare coverage yet for Prolaris, Myriad is conducting a study, called PROCEED, that it hopes will sway Medicare contractor Noridian to cover the diagnostic. The company has said it is on track to submit data from this registry to Medicare by late summer and expects to hear a decision about test coverage in calendar year 2014 (PGx Reporter 5/8/2013).

During the annual investor day last week, Myriad officials highlighted the gene panel for Prolaris, which features genes involved in cell cycle progression, and noted this as one of the advantages of its test over standard methods. “The Prolaris score measures how fast the tumor is growing. We look at the cell proliferation to look at a component of cancer that is not looked at by current clinical pathologic features,” Bill Rusconi, head of Myriad’s urology division, said.

“So, pathology like PSA score … only look at how far the tumor is progressed … [and] how advanced that tumor is. So, that’s only half of the picture because an advanced tumor could have been smoldering for 20 years, and may not go much further in the short term,” he noted. On the other hand, Rusconi added that a less advanced tumor could be progressing very quickly.

Another distinguishing point for the Prolaris test, according to Myriad, is that it is indicated for patients who are deemed to be at low and high risk by standard measures. Prostate cancer patients deemed to be at high risk of progression by standard clinical measures wouldn’t qualify for testing by Genomic Health’s test. Rusconi estimated that if Prolaris tested around 200,000 patients with localized prostate cancer to gauge the aggressiveness of their disease, the market opportunity for the test would be $700 million.

Myriad executives declined to comment on competing prostate cancer molecular tests, particularly Genomic Health’s product, noting that there isn’t a lot of published data to make any judgments. “We haven’t really seen any published data from any other competitor product. And so, I think in the absence of that, until data have made it through the peer review process and been in publication, it’s always difficult to understand exactly what type of information is available,” Mark Capone, president of Myriad Genetics Laboratories, told investors.

New competition

Like Myriad’s BRACAnalysis test, which comprises more than 80 percent of its product revenues, Genomic Health’s Oncotype DX breast cancer recurrence tests is bringing in the majority of its product revenues. However, the company believes that its newly launched Oncotype DX prostate cancer test stands to be its largest market opportunity to date.

Last week, researchers from University of California, San Francisco, presented data from the first validation study involving the Oncotype DX prostate cancer test. The study involved nearly 400 prostate cancer patients considered low or intermediate risk by standard methods such as Gleason score and showed that when the Oncotype DX score was used in conjunction with other measures, investigators identified more patients as having very low risk disease who were appropriate for active surveillance than when they diagnosed patients without the test score.

More than one third of patients classified as low risk by standard measures in the study were deemed to be “very low risk” by Oncotype DX and therefore could choose active surveillance. Meanwhile, 10 percent of patients in the study were found by clinical measures to be at very low risk or low risk, but the Oncotype DX test deemed them as having aggressive disease that needed treatment.

Matthew Cooperberg of UCSF, who presented data from this validation study at the American Urological Association’s annual meeting last week, highlighted this feature of the Oncotype DX prostate cancer test to investors during a conference call last week. He noted that the test not only gauges which low-risk patients can confidently remain with active surveillance, but it also finds those patients who didn’t receive an accurate risk assessment based on standard clinical measures. “It’s also equally important that we identify the man who frankly should not be on active surveillance, because they’re out there,” he said.

Genomic Health has aligned its test with guidelines from the National Comprehensive Cancer Network, which has expressed concern about over-diagnosis and over-treatment in prostate cancer patients. In 2010, NCCN guidelines established a new “very low risk” category for men with clinically insignificant prostate cancer and recommended that men who fall into this category and have a life expectancy of more than 20 years should only be followed with active surveillance. In 2011, NCCN made the active surveillance criteria more stringent for men in the “very low risk” category.

In order to develop the prostate cancer test, Genomic Health collaborated with the Cleveland Clinic on six feasibility studies and selected the gene expression panel after analyzing 700 genes on tissue samples from 700 patients. The commercial test analyzes the expression of 17 genes across four biological pathways.

Genomic Health executives suggested to investors that in determining the aggressiveness of prostate cancer a test that gauges critical genes in multiple pathways involved in the disease, as opposed to just one pathway, may be the better bet.

“After we selected those 700 [candidate] genes, we were completely agnostic as to what the best predictors would be. So, we let the genes do their thing and picked out the best performance,” said Eric Klein, chairman of Glickman Urological and Kidney Institute at the Cleveland Clinic and principal investigator for the original development studies for the Oncotype DX prostate cancer test. Referring to Myriad’s test, which assessed 46 cell cycle progression genes, Klein noted that while cell proliferation is important, it’s not the only pathway.

“So, I think one of the strengths of this assay is that it surveys the biology of the cancer better because it surveys other pathways,” he said. If a test only looks at genes in only one particular pathway, and the “score is low, you don’t know if you have missed the other underlying biology.”

This strategy of picking critical cancer-linked genes from multiple pathways has proven successful when launching Oncotype DX tests for breast cancer and colon cancer recurrence, company officials noted. Genomic Health’s prior experience launching molecular tests for cancer recurrence and the strength of the Oncotype DX brand will likely be advantages for the company.

Kim Popovits, CEO of Genomic Health, noted that the company has hired a “small sales force” to drive uptake of the prostate cancer test and reps will be targeting high-volume practices. “We have medical science liaisons that will be out there working to educate key opinion leaders with a similar approach to what we did in breast [cancer],” Popovits told investors. “We will begin to add to the sales organization as time goes on, as we see traction taking place, and as we move more towards payor reimbursement.”

The company plans to conduct a decision impact study as part of its effort to gain reimbursement coverage for the test. Genomic Health is also planning to do additional studies that will explore what level of active surveillance doctors should perform on patients who are deemed by the Oncotype DX test to be at very low or low risk.

The list price for the test is $3,820.

Other players

Although Myriad and Genomic Health are currently the main players in the prostate cancer molecular diagnostics space, the market will become an increasingly crowded one in the coming months.

Canadian firm GenomeDx is planning to launch a prostate cancer molecular diagnostic later this year, called Decipher. The company recently presented data at a medical conference on the test’s clinical validity and utility in predicting which patients are at risk of recurrence and metastasis after prostate cancer surgery. The company has said it has 22 studies underway with the Decipher test involving 4,000 patients (PGx Reporter 2/20/2013).

BioTheranostics recently published a study in the Proceedings of the National Academy of Sciences about its new 32-gene signature test, dubbed Prostate Cancer Index, which gauges PSA recurrence. In the study, which involved 270 tumor samples for patients treated with radical prostatectomy, the RT-PCR test (developed in collaboration with Massachusetts General Hospital) predicted PSA recurrence and had added value over standard measures such as Gleason score, tumor stage, surgical margin status, and pre-surgery PSA levels. The only other measure with significant prognostic value was surgical margin status.

The test could separate patients into groups based on PSA recurrence and whether they would develop metastatic disease within a 10-year period. PCI found that patients with a high risk score had a 14 percent risk of metastasis, while those in the low-risk group had a zero percent risk of metastasis. “In particular, this information may be useful at the biopsy stage, so that clinicians can better assess which patients can consider active surveillance versus those who should consider immediate treatment,” BioTheranostics CEO Richard Ding told PGx Reporter.

BioTheranostics has not yet determined when it will launch PCI. However, the company is planning additional follow-on studies to demonstrate the clinical utility of the test, including one study involving patients on active surveillance after having an initial prostate biopsy.

      Turna Ray is the editor of GenomeWeb’s Pharmacogenomics Reporter. She covers pharmacogenomics, personalized medicine, and companion diagnostics. E-mail Turna Ray or follow her GenomeWeb Twitter account at @PGxReporter.

 

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EARLY DETECTION OF PROSTATE CANCER: AUA GUIDELINE

Author-Writer: Dror Nir, PhD

 

 When reviewing the DETECTION OF PROSTATE CANCER section on the AUA website , The first thing that catches one’s attention is the image below; clearly showing two “guys” exploring with interest what could be a CT or MRI image…..

 fig 1

But, if you bother to read the review underneath this image regarding EARLY DETECTION OF PROSTATE CANCER: AUA GUIDELINE produced by an independent group that was commissioned by the AUA to conduct a systematic review and meta-analysis of the published literature on prostate cancer detection and screening; Panel Members: H. Ballentine Carter, Peter C. Albertsen, Michael J. Barry, Ruth Etzioni, Stephen J. Freedland, Kirsten Lynn Greene, Lars Holmberg, Philip Kantoff, Badrinath R. Konety, Mohammad Hassan Murad, David F. Penson and Anthony L. Zietman – You are bound to be left with a strong feeling that something is wrong!

The above mentioned literature review was done using rigorous approach.

“The AUA commissioned an independent group to conduct a systematic review and meta-analysis of the published literature on prostate cancer detection and screening. The protocol of the systematic review was developed a priori by the expert panel. The search strategy was developed and executed

by reference librarians and methodologists and spanned across multiple databases including Ovid Medline In-Process & Other Non-Indexed Citations, Ovid MEDLINE, Ovid EMBASE, Ovid Cochrane Database of Systematic Reviews, Ovid Cochrane Central Register of Controlled Trials and Scopus. Controlled vocabulary supplemented with keywords was used to search for the relevant concepts of prostate cancer, screening and detection. The search focused on DRE, serum biomarkers (PSA, PSA Isoforms, PSA kinetics, free PSA, complexed PSA, proPSA, prostate health index, PSA velocity, PSA

doubling time), urine biomarkers (PCA3, TMPRSS2:ERG fusion), imaging (TRUS, MRI, MRS, MR-TRUS fusion), genetics (SNPs), shared-decision making and prostate biopsy. The expert panel manually identified additional references that met the same search criteria”

While reading through the document, I was looking for the findings related to the roll of imaging in prostate cancer screening; see highlighted above. The only thing I found: “With the exception of prostate-specific antigen (PSA)-based prostate cancer screening, there was minimal evidence to assess the outcomes of interest for other tests.

This must mean that: Notwithstanding hundreds of men-years and tens of millions of dollars which were invested in studies aiming to assess the contribution of imaging to prostate cancer management, no convincing evidence to include imaging in the screening progress was found by a group of top-experts in a thorough and rigorously managed literature survey! And it actually  lead the AUA to declare that “Nothing new in the last 20 years”…..

My interpretation of this: It says-it-all on the quality of the clinical studies that were conducted during these years, aiming to develop an improved prostate cancer workflow based on imaging. I hope that whoever reads this post will agree that this is a point worth considering!

For those who do not want to bother reading the whole AUA guidelines document here is a peer reviewed summary:

Early Detection of Prostate Cancer: AUA Guideline; Carter HB, Albertsen PC, Barry MJ, Etzioni R, Freedland SJ, Greene KL, Holmberg L, Kantoff P, Konety BR, Murad MH, Penson DF, Zietman AL; Journal of Urology (May 2013)”

It says:

“A systematic review was conducted and summarized evidence derived from over 300 studies that addressed the predefined outcomes of interest (prostate cancer incidence/mortality, quality of life, diagnostic accuracy and harms of testing). In addition to the quality of evidence, the panel considered values and preferences expressed in a clinical setting (patient-physician dyad) rather than having a public health perspective. Guideline statements were organized by age group in years (age<40; 40 to 54; 55 to 69; ≥70).

RESULTS: With the exception of prostate-specific antigen (PSA)-based prostate cancer screening, there was minimal evidence to assess the outcomes of interest for other tests. The quality of evidence for the benefits of screening was moderate, and evidence for harm was high for men age 55 to 69 years. For men outside this age range, evidence was lacking for benefit, but the harms of screening, including over diagnosis and over treatment, remained. Modeled data suggested that a screening interval of two years or more may be preferred to reduce the harms of screening.

CONCLUSIONS: The Panel recommended shared decision-making for men age 55 to 69 years considering PSA-based screening, a target age group for whom benefits may outweigh harms. Outside this age range, PSA-based screening as a routine could not be recommended based on the available evidence. The entire guideline is available at www.AUAnet.org/education/guidelines/prostate-cancer-detection.cfm.”

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

From AUA2013: “Histoscanning”- aided template biopsies for patients with previous negative TRUS biopsies

Imaging-biomarkers is Imaging-based tissue characterization

On the road to improve prostate biopsy

State of the art in oncologic imaging of Prostate

Imaging agent to detect Prostate cancer-now a reality

Scientists use natural agents for prostate cancer bone metastasis treatment

Today’s fundamental challenge in Prostate cancer screening

ROLE OF VIRAL INFECTION IN PROSTATE CANCER

Men With Prostate Cancer More Likely to Die from Other Causes

New Prostate Cancer Screening Guidelines Face a Tough Sell, Study Suggests

New clinical results supports Imaging-guidance for targeted prostate biopsy

Prostate Cancer: Androgen-driven “Pathomechanism” in Early-onset Forms of the Disease

Prostate Cancer and Nanotecnology

Prostate Cancer Cells: Histone Deacetylase Inhibitors Induce Epithelial-to-Mesenchymal Transition

Imaging agent to detect Prostate cancer-now a reality

Scientists use natural agents for prostate cancer bone metastasis treatment

ROLE OF VIRAL INFECTION IN PROSTATE CANCER

Prostate Cancers Plunged After USPSTF Guidance, Will It Happen Again?

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Reporter: Aviva Lev-Ari, PhD, RN

Dr. Lev-Ari was Director @ SRI International in the mid 1980s.

Denong Wang

Distinguished Scientist and Senior Program Director, Tumor Glycomics Laboratory, Center for Cancer and Metabolism
Denong Wang

Denong Wang, Ph.D., is an SRI distinguished scientist and senior program director of the Tumor Glycome Laboratoryin the Center for Cancer and Metabolism in SRI Biosciences. Wang’s long-term research interest is in the carbohydrate moieties that are critical for self/non-self recognition and induction of antibody responses.

Wang’s team has established multiple platforms of carbohydrate microarrays and introduced these glycomics tools to explore the structural and antigenic diversities of the glycome. The main research focus of his lab is in the immunogenic sugar moieties. In the past few years, his group has contributed to the identification of immunologically potent glycan markers of SARS-CoV, Bacillus anthracis exosporium, and a number of human cancers.

Wang received his Ph.D. in immunology and glycobiology with the late Professor Elvin A. Kabat at Columbia University in 1993. After that, he entered the developing field of post-genomics research. Before joining SRI in 2010, he served as head of the Functional Genomics Division at Columbia University’s Genome Center from 1998 to 2003 and was director of Stanford University’s Tumor Glycome Laboratory from 2007 to 2010.

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A Blood Test to Identify Aggressive Prostate Cancer

By Denong Wang at 9:15 AM PDT, Wed May 8, 2013

tumor glycomicsProstate cancer is the second most common cancer in American men, killing nearly 30,000 per year. In 2004, I attended a conference where one of the nation’s leading researchers in the field declared that the gold-standard test for this disease was not successful at identifying dangerous invasive tumors. That triggered my interest in how to address the challenge of developing a blood test to detect the deadly form of prostate cancer.

After nearly a decade, my collaborators and I have found the first marker that specifically identifies the approximately six to eight percent of prostate cancers that are considered “aggressive,” meaning they will migrate to other parts of the body, at which point they are very difficult to treat. Although we have confirmed this marker, there is much to be done before a clinical application can be developed.

If further study confirms that the test is clinically reliable, it can provide a much-needed tool to differentiate between aggressive cancer and the majority of cases, which are slow-growing tumors with a low probability of migrating to other parts of the body (and thus don’t require special treatment, such as radical prostatectomy).

The current standard test looks at elevated blood prostate-specific antigen (PSA) levels, known as the PSA test. Dr. Thomas Stamey, an emeritus faculty member and urologist at the Stanford University School of Medicine, published his original findings in 1987 linking elevated blood PSA levels to prostate cancer. In 2004, Dr. Stamey declared that the PSA test was no longer useful for the diagnosis of prostate cancer. Rather, an elevated PSA level is now known to reflect the volume increase of a prostate, which could either be associated with a harmless increase in prostate size called benign prostatic hyperplasia (BPH), or be caused by cancer.

I began collaborating with Dr. Stamey and his Stanford colleague Dr. Donna Peehl to look for a new prostate cancer marker, hopefully one that would indicate the presence of aggressive prostate cancer through a blood test.  This is a very active area of research, with scientists exploring the idea from (1) a genomics perspective, (2) a proteomics perspective, and (3) a glycomics perspective, the latter of which entails using carbohydrate-based markers to identify cancer. My focus is the third area, where we are concentrating on how the immune system recognizes changes in the carbohydrates found on the surface of cancer cells compared with those on the surface of normal cells.  

SRI’s Tumor Glycome Laboratory has discovered a marker that appears to be associated with aggressive prostate cancer. The marker is an antibody that is produced against a carbohydrate molecule on the surface of aggressive prostate cancer cells, and is expressed in increasing levels that correlate with cancer severity. We call it a “cryptic” biomarker, since it only becomes an immunological target if something goes awry in the cell, such as a viral infection or the malignant transformation of normal cells to cancer.

This biomarker has the potential, with further development, to be used as a test to help diagnose aggressive prostate cancer. It is rewarding to have reached this point in our understanding of prostate cancer and toward a diagnostic test that ultimately could save lives.

Our research findings were published last year in the Journal of Proteomics & Bioinformatics (5:090-095, DOI:10.4172/jpb.1000218). Our latest study, published in Drug Development Research, lays the foundation for predicting which prostate cancer patients may develop more aggressive forms of the disease and directs the future design of more effective treatments [14(2):65-80, DOI: 10.1002/ddr.21063].

Anti‐Oligomannose Antibodies as Potential Serum Biomarkers of Aggressive Prostate Cancer

Abstract

This study bridges a carbohydrate microarray discovery and a large‐scale serological validation of anti‐oligomannose antibodies as novel serum biomarkers of aggressive prostate cancer (PCa). Experimentally, a Man9‐cluster‐specific enzyme‐linked immunosorbent assay was established to enable sensitive detection of anti‐Man9 antibodies in human sera. A large‐cohort of men with PCa or benign prostatic hyperplasia (BPH) whose sera were banked at Stanford University was characterized using this assay. Subjects included patients with 100% Gleason grade 3 cancer (n = 84), with Gleason grades 4 and/or 5 cancer (n = 204), and BPH controls (n = 135). Radical prostatectomy Gleason grades and biochemical (PSA) recurrence served as key parameters for serum biomarker evaluation. It was found that IgGMan9 and IgMMan9 were widely present in the sera of men with BPH, as well as those with cancer. However, these antibody reactivities were significantly increased in the subjects with the largest volumes of high grade cancer. Detection of serum IgGMan9 and IgMMan9 significantly predicted the clinical outcome of PCa post‐radical prostatectomy. Given these results, we suggest that IgGMan9 and IgMMan9 are novel serum biomarkers for monitoring aggressive progression of PCa. The potential of oligomannosyl antigens as targets for PCa subtyping and targeted immunotherapy is yet to be explored.

Authors: Denong Wang, Laila Dafik, Rosalie Nolley, Wei Huang, Russell D. Wolfinger, Lai‐Xi Wang, Donna M. Peehl
Journal: Drug Development Research
Year: 2013
Pages: n/a
DOI: 10.1002/ddr.21063
Publication date: 11-02-2013

Proteomics & Bioinformatics

N-glycan Cryptic Antigens as Active Immunological Targets in Prostate

Cancer Patients

Denong Wang*

Tumor Glycomics Laboratory, Center for Cancer Research, Biosciences Division, SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025, USA

*Corresponding author: Dr. Denong Wang, Tumor Glycomics Laboratory,

Biosciences Division, SRI International, 333 Ravenswood Avenue, Menlo

Park, CA 94025, USA, Tel: +1 650 859-2789; Fax: +1 650 859-3153; E-mail:

denong.wang@sri.com

Received March 07, 2012; Accepted April 13, 2012; Published April 30, 2012

Citation: Wang D (2012) N-glycan Cryptic Antigens as Active Immunological

Targets in Prostate Cancer Patients. J Proteomics Bioinform 5: 090-095.

doi:10.4172/jpb.1000218

Copyright: © 2012 Wang D.

Abstract

Although tumor-associated abnormal glycosylation has been recognized for decades, information regarding host recognition of the evolving tumor glycome remains elusive. We report here a carbohydrate microarray analysis of a number of tumor-associated carbohydrates for their serum antibody reactivities and potential immunogenicity in humans. These are the precursors, cores and internal sequences of N-glycans. They are usually masked by other sugar moieties and belong to a class of glyco-antigens that are normally “cryptic”. However, viral expression of these carbohydrates may trigger host immune responses. For examples, HIV-1 and SARS-CoV display Man9 clusters and tri- or multi-antennary type II (Galβ1→4GlcNAc) chains (Tri/m-II), respectively; viral neutralizing antibodies often target these sugar moieties. We asked, therefore, whether prostate tumor expression of corresponding carbohydrates triggers antibody responses in vivo. Using carbohydrate microarrays, we analyzed a panel of human sera, including 17 samples from prostate cancer patients and 12 from men with Benign Prostatic Hyperplasia (BPH).

We observed that IgG antibodies targeting the Man9- or Tri-/m-II-autoantigens are readily detectable in the sera of men with BPH, as well as those with cancer. Importantly, these antibody activities were selectively increased in prostate cancer patients. Thus, human immune systems actively recognize these N-glycan cryptic carbohydrates and produce targeting antibodies. This finding shads a light on a class of previously less studied immunological targets of human cancers. Identifying the diagnostic, prognostic and therapeutic values of these targets will require further investigation.

http://www.omicsonline.org/0974-276X/JPB-05-090.pdf

 

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On the road to improve prostate biopsy

Author-Writer: Dror Nir, PhD

Urologists are in constant search for a method that will improve the outcome of prostate biopsy, particularly when it comes to ruling-in and ruling-out clinically significant prostate cancer. As stated in my recent post – State of the art in oncologic imaging of Prostate; “The disease’s staging and related prognosis are determined during diagnosis based on PSA level and the Gleason score of biopsy’s samples. Although prostate-specific antigen (PSA) screening resulted in the diagnosis of prostate cancer at earlier stages and with lower Gleason scores, it has also contributed to concerns about over-diagnosis, overtreatment of clinically insignificant disease, associated treatment-related toxicity, and escalating costs”. I already reported in the past on research conduc ted in this area; New clinical results supports Imaging-guidance for targeted prostate biopsy and Knowing the tumor’s size and location, could we target treatment to THE ROI by applying imaging-guided intervention? Today I report on recent publication presenting the advantage of using targeted trans-perineal biopsy following HistoScanning imaging instead of systematic TRUS biopsies: Computer-aided (HistoScanning) Biopsies Versus Conventional Transrectal Ultrasound-guided Prostate Biopsies: Do Targeted Biopsy Schemes Improve the Cancer Detection Rate? (Moritz F. Hamann, Claudius Hamann, Eckhard Schenk, Amr Al-Najar, Carsten M. Naumann, and Klaus-Peter Jünemann, Urology, Volume 81, Issue 2, February 2013, Pages 370-375)

I have mentioned HistoScanning (ultrasound-based tissue characterization technology which I have invented and developed to a medical device) in many of my previous posts. HistoScanning for prostate is a specific HistoScanning application that is applied to the ultrasound’s raw signal (not the image) following a comprehensive scan of the prostate capturing its entire volume. The whole process takes about ten minutes and the output is a digital 3D map of the prostate gland where locations suspicious of presenting with prostate cancer are indicated.

HistoScanning report with 2, bilateral, basal lesions.

HistoScanning report with 2, bilateral, basal lesions.

 

The urologist translates such map into a “prostate regional biopsy scheme” when planning his biopsies and direct the needle, under ultrasound guidance, to these predefined suspicious locations.

 The systematic biopsy patterns targeted 7 sectors bilaterally: transition zone, apex, center, and base, each medially and laterally.

The systematic biopsy patterns targeted 7 sectors bilaterally: transition zone, apex, center, and base, each medially and laterally.

In that sense, the workflow is similar to using MRI for tumor detection and creating a tumor map for targeting the biopsy.

As reasoning for conducting the study the investigators argue that: “Exact staging of prostate cancer before treatment is essential for relevant therapeutic decision making. Current procedures, such as nerve-sparing prostatectomy and brachytherapy, as well as active surveillance and future focal treatment options, depend on the reliable identification of cancerous lesions within the prostate. Systematic prostate biopsies with at least 10 to 12 cores are the current standard method to detect and locate significant prostate cancer, as scientific evidence during the last decades has shown. Nevertheless, there are no homogeneous data concerning the required number of cores and the technical approach of prostate biopsy procedures. The unstable histologic results on active surveillance and the well-known discrepancy between transrectal diagnostics and radical prostatectomy specimens underline the neces­sity to develop reliable diagnostic tools for precise detection and localization of prostate cancer. Recent data on HistoScanning computer-aided ultra-sonography have shown favorable results. To generate a greater diagnostic yield than systematic needle biopsies, we integrated HistoScanning-guided targeted biopsies in our general prostate biopsy regimen. We report the cancer detection rate in a prospective series of 80 patients.”

The study’s objective was: “To define potential improvement in prostate cancer detection by application of a computer-aided, targeted, biopsy regimen using HistoScanning.”

Materials and Methods: “The data were collected prospectively from 80 men who consecutively underwent a systematic 14-core prostate biopsy supplemented by targeted transrectal and perineal ultrasound-guided biopsies. All biopsies were performed between March 2011 and September 2011. Indications for prostate biopsy were suspicious findings at the digital rectal examination (DRE), or serum prostate-specific antigen (PSA) level >10 ng/mL, or both. In case of elevated serum PSA levels >4 ng/mL a PSA-velocity of >0.75 ng/mL p.a. and free-to-total PSA ratio <15% were seen as the indication for prostate biopsies. Thirty-six patients had undergone a previous transrectal prostate biopsy. All patients were informed of the mode of the extended prostate biopsy scheme and its potential complications. All patients provided written informed consent for the procedure.After indication and before starting the biopsy procedure, all patients underwent a standardized 3-dimensional (3D) transrectal ultrasound (TRUS) with an end-fire array of a BK 8818 probe. Computer-aided analysis of the raw (radio-frequency) back-scatter data was performed by using the Conformite Europeene-marked and commercially available HistoScanning device, admitted for medical use in the Euro­pean Union (software version 2.1, Advanced Medical Diag­nostics, Belgium).”

“Each patient was diagnosed preoperatively by HistoScanning, defining a maximum of 3 suspicious areas. These areas were biopsied, both transrectally and via the perineum, with a maximum of 3 cores per location.”

Results: “We detected prostatitis in 30 patients (37.5%), premalignant lesions in 10 (12.5%), and prostate cancer in 28 (35%). The transrectal technique was used to detect 78.6% of all cancers using 14 cores by systematic biopsy. With a maximum of 9 targeted cores, 82.1% of all cancers were detected with the targeted perineal approach and 53.6% were detected with the targeted transrectal approach. Although our data did not show significant difference in the performance of targeted transperineal compared with systematic transrectal biopsies, the detection rate of targeted transrectal biopsies was significantly lower.”

 table

Conclusion: “The presented targeted biopsy scheme achieved an overall detection rate of 85% of prostate-specific antigen–relevant pathologic lesions within the prostate. Thus, the presented procedure shows an improved detection rate compared with standard systematic prostate biopsies, and the number of cores required is reduced. Furthermore, the perineal HistoScanning-aided approach seems to be superior to the transrectal approach with respect to the prostate cancer detection rate. The presented procedure might be a step toward reliable ultrasound-based tissue characterization and toward fulfilling the requirements of novel therapeutic strategies.”

 

The authors’ included an elaborated discussion on the background to their study and its results. This discussion is important for understanding the limitation of the study results and for putting the authors conclusion into balanced context: “When other solid-organ cancer guidelines are compared with prostate cancer guidelines, the common methods of prostate cancer detection are unmasked as an outmoded concept because cancer detection is based on chance as a result of a blinded, subjective examination. A systematic biopsy with at least 10 to 12 cores is considered the standard procedure in prostate cancer diagnostics to date. 1,2 The continuous increase in the number of biopsy cores taken over the last years has predictably improved the detection rate, but several studies report detection rates of only 30% to 40% even in repeated biopsies. 5,9 It is noteworthy that the recommendations must be seen as a compromise bbetween the cancer detection rate and the invasiveness of the surgical procedure. Modern diagnostic procedures, including magnetic resonance imaging, elastography, computerized analysis of TRUS/artificial neuronal network analysis, and HistoScanning, try to overcome this principle of approach.7,10,11 The current therapeutic concepts and further currently evolving therapy strategies depend on sophisticated prostate cancer diagnostics. It is more important than ever to look for ways to detect and locate the cancer before subjecting patients to more or less invasive procedures as the indication for surgical treatment or prostate-preserving (focal) tumor therapy. The results of magnetic resonance imaging for prostate cancer detection are very promising so far and show a sensitivity of up to 80%. Elastography has also shown promising capabilities for cancer detection, with a recent review article reporting that several studies show 74% to 75% sensitivity.11 HistoScanning has shown 93% sensitivity in detecting and locating prostate cancer. 12 As a matter of principle, our study is unable to report on the accuracy or sensitivity of prostate cancer detection because the exact number of cancer lesions in our patients collective remains incomputable. Integration of HistoScanning for guided, targeted biopsies helped us achieve a prostate cancer detection rate of 35%. These data are lower than results from current publications on initial prostate biopsies but higher than those of repeated biopsy protocols.4,5,13 Given that tumors looked for during initial biopsies are usually large and easy to detect, we believe that this finding is caused by the smaller overall risk of cancer in a repeated biopsy setting, as was the case in 37.5% of our patients (0.61 biopsies per patient). Overall, HistoScanning seems to improve selective targeting of suspicious prostate lesions. Taking into account all malignant, premalignant, and atypical histologic findings, including prostate cancer, atypical small acinar proliferations, and high-grade prostatic intraepithelial  eoplasia, the detection rate of relevant prostatic lesions by specimens from perineal-targeted biopsies rises to 47.5% and 85%, including prostatitis, respectively. Apart from the high quality of the HistoScanning tissue analysis, we believe in a significant effect of the technical approach used to perform the biopsy. As our data show, prostate cancer detection rates from specimens obtained from perineal-targeted biopsies differed significantly from the transrectal-targeted biopsy regimen, a difference that occurred independently from previous tissue analysis because both targeted approaches are aligned to the same scanning process. Compared with the transrectal approach, the perineal biopsy technique might reduce variables that can influence the needle placement. Furthermore, longitudinal biopsy punches following the axis of the prostate seem to allow more accurate sampling of the anterior part. Theoretically, because previous studies reported inhomogeneous results comparing transrectal and transperineal prostate biopsies.3,4,13 The use of a 14-gauge needle in perineal biopsies might be responsible for a systematic bias because it possibly yields more tissue than transrectal cores. Despite this potential advantage, systematic transrectal biopsies do not reflect a significant difference in the detection rate. Nevertheless, due to the individual setting, our study is unable to report standardized results on the accuracy of comparing transrectal and transperineal needle placement. Template-guided mapping biopsies have recently attracted attention because of the high rate of cancer detection as initial (75%) and even repeat biopsy procedures (46%). 14 It notably increases the ability to locate and differentiate cancer foci within the prostatic gland, implicating mapping biopsies for active surveillance or focal treatment purposes regardless of the considerable surgical trauma generated by the use of extended biopsy protocols. A reduction of tissue trauma by generating a greater diagnostic yield would be a favorable methodologic aspect as initiated by our study. Regarding cancer detection, the presented data show no significant differences between the perineal-targeted and transrectal-targeted systematic biopsy regimen, but even though considerably fewer tissue samples (14 vs 9 cores; -35%) were taken from selected prostate areas, we detected no significant limitations by the perineal approach. These data are even more encouraging when bearing in mind that the number of samples represents a crucial factor in prostate cancer detection rates, as recently reported. A critical issue in the present study is in the implementation of the modified biopsy procedures. Although the surgeons at our center are experienced in using TRUS, our data show a learning curve during the first 80 procedures. In addition, the overlaying of the HistoScanning image analysis to the B-mode grey-scale live ultrasound picture is done by the surgeon performing the biopsy. This process implies a bias in individual interpretation of the TRUS picture and manual needle guidance. The online fusion of HistoScanning with the ultrasound image presumably would increase the handling accuracy. Further methodologic limitations lie in the heterogeneous and small collective of patients that were included in the study. With regard to the reasonably high number of previous negative biopsy specimens, patient selection can affect the hit rate of positive biopsy specimens. This circumstance might make the cancer detection frequency with HistoScanning look relatively small in this particular study compared with other diagnostic methods in patients undergoing an initial biopsy, but this is due to the daily routine in an academic referral center.

For completeness of this reporting and before stating my own conclusion I bring here below two comments that were made, one by Dr. Stephen Jones of Glickman Urological and Kidney Institute, Cleveland, Ohio and the reply by the first author:

COMMENT

The promise of image-guided diagnosis and management of prostate cancer has been frustratingly elusive. Early pioneers of prostate ultrasound imaging reported that hyperechoic lesionswere indicative of malignancy, but it rapidly became clear that the opposite was actually more realistic. Even so, these hypoechoic lesions were soon shown to be poor indicators of prostate cancer. Thus, the value of visual abnormalities on grey-scale prostate ultrasound imaging remains essentially negligible with current technology. As a result, a number of alternative imaging modalities have been developed and introduced with great excitement. Typically, images in the publications showcase an apparently obvious cancer standing out in contrast to adjacent benign tissues. Unfortunately, the data still reveal minimal value from most of these technologies, and those reported in this article are similarly disappointing. HistoScanning demonstrated interesting color images, but coupled with a transperineal-targeted biopsy found exactly one more case of prostate cancer than did the current standard of care—the 14-core extended transrectal biopsy. This “difference” is actually statistically identical (P >.99). Exactly the same number of patients (n¼ 4) was found exclusively by both transperineal HistoScan-targeted biopsy as with standard transrectal biopsy, and when targeted using the transrectal approach, the technology actually missed almost half of the cancers that were identified overall. Furthermore, these data do not support the suggestion that 9 cores are less morbid or traumatic than 14 cores, and the literature is replete with reports demonstrating this is simply not true. This is especially misleading when those 9 cores come at the cost, morbidity, time, and complexity of an operation such as this performed under general anesthesia. So the real question remains whether HistoScanning or any emerging technology to image the prostate—improves visualization of prostate cancer. Although magnetic resonance imaging is beginning to show notable promise, the clinical value of most other modalities remains mostly anecdotal. As one whose desire for a solution remains frustratingly unfulfilled, I hope that some imaging technique will demonstrate clinical value during my career. J. Stephen Jones, M.D., Department of Regional Urology, Glickman Urological and Kidney Institute, Cleveland Clinic Foundation, Cleveland, Ohio

REPLY

In accordance with your comprehensive notes, we have to search for diagnostic improvement and underline the need further investigations in the field of prostate cancer diagnostics and staging. Minimally invasive techniques, focal and targeted therapy modalities, and low-risk cancer surveillance probably are future treatment modalities for prostate malignancies that progressively challenge common diagnostic pathways. Sophisticated therapy strategies will require reliable staging results. The constant increase of cores taken during systematic prostate biopsy apparently will not overcome the well-known diagnostic uncertainties. Consequently, imaging techniques and methods of biopsy targeting will gain in importance. Clearly, the presented data do not show significant improvement in the overall detection rate of prostate cancer in our patient cohort. Further, the maximum number of 9 biopsy cores must be attributed to the initial study design and will undergo further investigation; however, the results rather support the study approach than reduce its validity. Considering the indeterminate number of cancers, the proof of superiority remains incomputable. Compared with the current standard of care of 12 to 14 cores, we detected no significant limitations, although perineal-targeted biopsies took significantly fewer cores (3-9 cores [35%]). Maintaining the detection rate unchanged and focusing on 1 to 3 preselected suspicious index lesions display a proof of principle rather than disappointing results. In line with future treatment options mentioned above, any less invasive, focused diagnostic procedure represents an encouraging advance compared with the common and recommended practice of a nonselective, systematic biopsy of the prostate to harbor cancerous tissue. Moritz F. Hamann, M.D., Department of Urology and Pediatric Urology, University of SchleswigeHolstein, Campus Kiel, Kiel, Germany

As mentioned by the authors, further improvement of the outcome of HistoScanning-based targeted biopsies of prostate is expected when an implementation of image-fusion application between the “off-line” generated 3D tumor map and the real-time ultrasound guiding the needle will be available; similar to the results presented already when using ultrasound-MRI image fusion applications for prostate biopsy. Of course, the ultimate biopsy workflow (which I am currently engaged in developing) that urologist are asking for is the one comprised of real-time ultrasound-based tissue characterization and real-time ultrasound guidance of the needle to the lesion.

References

1. Heidenreich A, Bellmunt J, Bolla M, et al. EAU guidelines on prostate cancer. Part 1: screening, diagnosis, and treatment of clinically localised disease. Eur Urol. 2011;59:61-71.

2. National Comprehensive Cancer Network. Clinical Practice Guidelines in Oncology: Prostate Cancer Early Detection. Available at http://www.nccn.org 2011 Accessed May 2011.

3. Abdollah F, Novara G, Briganti A, et al. Trans-rectal versus transperineal saturation re-biopsy of the prostate: is there a difference in cancer detection rate? Urology. 2011;77:921-925.

4. Hara R, Yoshimasa J, Tomohiro F, et al. Optimal approach for prostate cancer detection as initial biopsy: prospective randomized study comparing transperineal versus transrectal systematic 12-core biopsy. Urology. 2008;71:191-195.

5. Patel AR, Jones JS. Optimal biopsy strategies for the diagnosis and staging of prostate cancer. Curr Opin Urol. 2009;19:232-237.

6. Al Otaibi M, Ross P, Fahmy N, et al. Role of repeated biopsy of the prostate in predicting disease progression in patients with prostate cancer on active surveillance. Cancer. 2008;113:286-292.

7. Braeckman J, Autier P, Garbar C, et al. Computer-aided ultrasonography (HistoScanning): a novel technology for locating and characterizing prostate cancer. BJU Int. 2008;101:293-298.

8. Braeckman J, Autier P, Soviany C, et al. The accuracy of transrectal ultrasonography supplemented with computer-aided ultrasonography for detecting small prostate cancers. BJU Int. 2008;102:1560-1565.

9. Presti JC Jr, O’Dowd G, Miller C, et al. Extended peripheral zone biopsy schemes increase cancer detection rates and minimize variance in prostate specific antigen and age related cancer rates: results of a community multi-practice study. J Urol. 2003;169:125-129.

10. Turkbey B, Mani H, Shah V, et al. Multiparametric 3T prostate magnetic resonance imaging to detect cancer: histopathological correlation using prostatectomy specimens processed in customized magnetic resonance imaging based molds. J Urol. 2011;186: 1818-1824.

11. Trabulsi EJ, Sackett D, Gomella L, et al. Enhanced transrectal ultrasound modalities in the diagnosis of prostate cancer. Urology. 2010;76:1025-1033.

12. Simmons LA, Autier P, Zat_ura F, et al. Detection, localisation and characterisation of prostate cancer by Prostate HistoScanning. BJU Int. 2012;110:28-35.

13. Emiliozzi P, Corsetti A, Tassi B, et al. Best approach for prostate cancer detection: a prospective study on transperineal versus transrectal six-core prostate biopsy. Urology. 2003;61:961-966.

14. Taira AV, Merrick GS, Galbreath RW, et al. Performance of transperineal template-guided mapping biopsy in detecting prostate cancer in the initial and repeat biopsy setting. Prostate Cancer Prostatic Dis. 2010;13:71-77.

 

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

Prostate Cancer: Androgen-driven “Pathomechanism” in Early-onset Forms of the Disease

Prostate Cancer and Nanotecnology

Prostate Cancer Cells: Histone Deacetylase Inhibitors Induce Epithelial-to-Mesenchymal Transition

Imaging agent to detect Prostate cancer-now a reality

Scientists use natural agents for prostate cancer bone metastasis treatment

ROLE OF VIRAL INFECTION IN PROSTATE CANCER

Prostate Cancers Plunged After USPSTF Guidance, Will It Happen Again?

Imaging agent to detect Prostate cancer-now a reality

Scientists use natural agents for prostate cancer bone metastasis treatment

Today’s fundamental challenge in Prostate cancer screening

ROLE OF VIRAL INFECTION IN PROSTATE CANCER

Men With Prostate Cancer More Likely to Die from Other Causes

New Prostate Cancer Screening Guidelines Face a Tough Sell, Study Suggests

New clinical results supports Imaging-guidance for targeted prostate biopsy

 

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