Thursday, October 10, 2013

PSA is still a Battle Ground

In the European Cancer Congress of 2013 one of the authors states in the Abstract the following:

We estimated the number of individuals needed to harm associated with PSA testing by applying different side effect estimates to a virtual population of 1,000 men aged 55–69 exposed to PSA testing and another 1,000 not exposed to PSA testing. 

Following a systematic literature review, we extracted results of PSA testing, biopsy rates and impact on prostate specific mortality from the European Randomized Study on Screening for Prostate Cancer (ERSPC) which is the study with the most favourable outcome to PSA screening. 

We also extracted, from reports with such information, data on mortality following prostatic biopsy, on mortality associated with radical prostatectomy as well as side effects of radical prostatectomy and hospitalisation rates following prostatic biopsy....

Overall, under the best scenario of screening efficiency, the prevention of 1 death from prostate cancer is associated with a significant additional adverse-effect burden from the biopsy and from the treatment of the additional prostate cancer diagnosed. 

These will severely impact the quality of life of patients and argues against using PSA testing for mass screening of prostate cancer. 

Note the phrasing, "number of individuals needed to harm.." , as a phrasing that any biopsy harms the patient. The problem often is that the biopsy may have been done poorly thus subjecting the patient to infection. That is a problem with practice and not procedure. Also note the phrase "severely impact the quality of life". What does that mean. If you have a biopsy and no PCa then you may have a small chance of an infection. If you have prepped properly and the Urologist is skilled and you take care afterwards, it is fairly probable that there is no problem.

On the other hand if you have PCa, then the issue is what to do. Is is indolent or aggressive? Most likely you cannot readily tell. So then what? Here is where the real issue is. Some men will look at family history to help. If your father died 20 months after diagnosis you may want to hedge your bets and be aggressive in treatment. But if dad and Uncle Joe died with it and it never did much to them, perhaps a different story. Thus, it all depends. No good answer!

As is stated in Healio:

“When discussing the use of the PSA test with patients, physicians should make them aware of the limitations of the test and the likelihood of it causing harm,” Boniol said. “We hope that our research findings will help clinicians to make decisions as to when to propose a PSA test, and to help the patient to decide whether or not to accept this recommendation.”

Now the problem with PCa in the first place is that like many cancers it does not behave the same in all people. Some few are very aggressive. Many are indolent. But to know which are which is still a work in progress.

In my Draft volume on Prostate Cancer  I have tried to examine this as best as possible. However even there we have missed may subtle but now potentially powerful forces in the epigenetic areas. Methylation may be playing a significant part as are miRNAs and lncRNAs. Thus, although we understand many pathways and translocations that may cause an aggressive PCa we do not fully understand the epigenetic forces.

Thus a blanket denial of use of PSA is a "head in the sand" strategy that will harm more than help, at least in my opinion. As for the above mentioned European Study, I have discussed its fatal flaws in my opinion and thus have no basis for its reliance.