Tuesday, September 14, 2010

Prostate Cancer: An Example of a Difference

I commented two days ago about the NY Times bemoaning the excess of the PSA test. I said then that the world is a collection of different people and averages only count when looking at very large groups. I pointed to the fact that each patient is different and the role of a physician is to try and integrate these differences in terms of the treatments provided. Moreover I stated that CER and its spawn deal with large group averages and that the soon to be mandated treatment protocols emanating from the wizards in Washington will apply only for that average person which frankly is non-existent.

In a recent UK Cancer Research news item they discuss one of these sub cases and demonstrate the efficacy of PSA testing. They state:

However, preliminary results from the latest study indicate that the degree of unnecessary treatment could be reduced by targeting PSA testing at men who have an increased risk of prostate cancer as a result of inheriting faulty BRCA1 or BRCA2 genes.

BRCA2 faults increase a man's risk of prostate cancer by up to seven-fold, while BRCA1 faults are thought to double risk in under-65s.

The IMPACT study is part-funded by Cancer Research UK and led by scientists at the Institute of Cancer Research (ICR) and the Royal Marsden NHS Foundation Trust.

Results for the first 300 men enrolled in the study, 205 of whom tested positive for faulty BRCA1 or BRCA2 genes, have now been published in the British Journal of Urology International and suggest that screening men with these gene faults may lead to earlier diagnosis of aggressive prostate cancers.

The BJUI article states:

Men aged 40–69 years from families with BRCA1 or BRCA2 mutations were offered annual prostate specific antigen (PSA) testing, and those with PSA >3 ng/mL, were offered a prostate biopsy. Controls were men age-matched (± 5 years) who were negative for the familial mutation.... The present study shows that the positive predictive value of PSA screening in BRCA mutation carriers is high and that screening detects clinically significant prostate cancer. These results support the rationale for continued screening in such men.

This is but another example where by studying the genetic details of a patient we can fine tune the use of testing. As I had stated before, indeed there are many cases of unnecessary surgery, yet there are many cases of lives saved. It is much too early for the wizards of Washington to tell us how to live, or die.