Author and Curator: Dror Nir, PhD
The management of men with prostate cancer is becoming one of the most challenging public health issues in the Western world. It is characterized by: over-diagnosis; over-treatment; low treatment efficacy; treatment related toxicity; escalating cost; and unsustainability [Bangma et al, 2007; Esserman et al, 2009]. How come? Well, everyone accepts that most prostate cancers are clinically insignificant. It is well known that all men above 65 harbor some sort of prostate cancer. Due to the current aggressive PSA-based screening, one in six men will be diagnosed with prostate cancer. Yet, the lifetime risk of dying of prostate cancer is only 3%. The problem is that, once diagnosed with prostate cancer, there is no accurate tool to identify those men that will die of the disease (in my previous post I mentioned 1:37). Currently, screening practices for prostate cancer are relying on the very unspecific prostate-specific-antigen (PSA) bio-marker test to determine which men are at higher risk of harboring prostate cancer and therefore need a biopsy. The existing diagnostic test is a transrectal ultrasound (TRUS) guided prostate biopsy aimed at extracting representative tissue from areas where cancer usually resides. This procedure suffers from several obvious faults:
1. Since the imaging tool used (B-mode ultrasound) is poor at detecting malignancies in the prostate, the probability of hitting a clinically significant cancer or missing a clinically insignificant cancer is subject to random error.
2. TRUS biopsy is also subjected to systematic error as it misses large parts of the prostate which might harbor cancer (e.g. apex and anterior zones). 
3. TRUS guided biopsies are often unrepresentative of the true burden of cancer as either the volume or grade of cancer can be underestimated.
In the last ten years I was leading the development of an innovative ultrasound-based technology, HistoScanningTM, aimed at improving the aforementioned faults;
Among the other most popular imaging modalities aimed at better prostate cancer detection in routine use are: MRI, Elastography, Contrast Enhanced Ultrasound etc…
In my future posts I will go into more detail on how these imaging modalities fit into routine workflow, how much they stay within budget constraints and what level of promise they bear for promoting personalized medicine. Stay tuned… Footnote: According to the final report by an advisory panel to the USA government: Doctors should no longer offer the PSA prostate cancer screening test to healthy men because they’re more likely to be harmed by the blood draw, and the chain of medical interventions that often follows than be helped; (http://www.usatoday.com/news/health/story/2012-05-21/prostate-cancer-screening-test-harmful/55118036/1) But then; what should be offered instead?
Other posts on this Scientific Website addressing Prostate Cancer
Prostate Cancers Plunged After USPSTF Guidance, Will It Happen Again?
New Prostate Cancer Screening Guidelines Face a Tough Sell, Study Suggests
ROLE OF VIRAL INFECTION IN PROSTATE CANCER
https://pharmaceuticalintelligence.com/2012/09/01/role-of-viral-infection-in-prostate-cancer/
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[…] See the original article here: Today's fundamental challenge in Prostate cancer screening … […]
Great images and like the Medical treatment related last sentences and the follow up post to wait for
This is an excellent presentation of improvement in imaging technology. I know that the debate about PSA and overdiagnosis has gone on for a good 15-20 years. Stamey presented his review of all the cases from his work at Stanford several years ago, and he was a developer of the sensitive method used today. He was disappointed with the results. He actually found that at a PSA level over 20+, the likelihood was that there is PC and that it is already metastatic. This was consistent with a study by MM Pinto et al. The difficulty then was that there was never validation of the best decision value for a PSA at the lower range, where medical decisions are made.
This is no longer the case. I cannot say more about a manuscript that should now be published in Clinical Biochemistry (Elsevier). (CLB-D-12-00159)
(Exciting and novel work).
Robustness of ProsVue™ linear slope for prediction of prostate cancer recurrence: Simulation studies on effects of analytical imprecision and sampling time variation
The authors present support for a method of use of the ProsVue linear slope for predicting PCa recurrence or survival within 8 years Post-RP. The 8 year time frame is validated using a small study, and treating the sample size problem using simulation of the predictors consisting of the mean and SDs of 3 PSA values taken postoperatively, and the log transform when Gaussian distribution is not found. The dependent variable in establishing the measured slope variances is whether or not there is recurrence.
Dr. Nir,
I added references for three posts on Prostate Cancer on this Site
Thanks Aviva,
I’ve read them. Great support to the claim that PSA screening is not suitable. If you combine inadequate screening with inadequate diagnosis (which was the subject of my post) you get the overtreatment situation Prostate cancer patients are in today.
Dror Nir, PhD
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Great to anticipate interesting post.
Very happy you joined my team. I posted to all my groups this post, will do it again on WED when all are at their desktop in the US
The main problem of PSA screening, as everybody knows, is that PSA was developed to detect recurrences! not early cancer still developing inside a functional prostate. Studies that I have conducted with HistoScanning showed that combining PSA with imaging based tissue characterization results with a much better correlation between cancer progression and PSA progression. I’ll probably get to it in one of my future posts…
[…] Image fusion is the process of combining multiple images from various sources into a single representative image. Ultrasound is the imaging modality used to guide Artemis in performing the biopsies. In this study MRI is used to overcome the “blindness” regarding tumor location. More on MRI’s cancer detection reliability can be found in my posts Imaging-guided biopsies: Is there a preferred strategy to choose? and Today’s fundamental challenge in Prostate cancer screening. […]
[…] Image fusion is the process of combining multiple images from various sources into a single representative image. Ultrasound is the imaging modality used to guide Artemis in performing the biopsies. In this study MRI is used to overcome the “blindness” regarding tumor location. More on MRI’s cancer detection reliability can be found in my posts Imaging-guided biopsies: Is there a preferred strategy to choose? and Today’s fundamental challenge in Prostate cancer screening. […]
[…] Today’s fundamental challenge in Prostate cancer screening […]
[…] Today’s fundamental challenge in Prostate cancer screening […]
[…] Today’s fundamental challenge in Prostate cancer screening […]
[…] Today’s fundamental challenge in Prostate cancer screening […]
[…] Today’s fundamental challenge in Prostate cancer screening […]
[…] Today’s fundamental challenge in Prostate cancer screening […]