Evidence-based Medicine and Prostate Cancer Treatment

Prostate cancer screening and treatment have been a major front in the evidence-based medicine and population health-oriented movements.  The perception has been, somewhat supported by research, that PSA screening was leading to discovery of many small and non-threatening cancers, which could be left alone without harm, but often were treated by surgery to remove the prostate or radiation or other treatment methods.  Biopsies following PSA results and any subsequent treatment obviously impose costs and can themselves lead to harmful outcomes.  (NEJM Article)  So the powers that be have recommended not doing routine PSA screening.  This means, however, that a number of cancers will not be discovered and that some of those will be aggressive and possibly even fatal.  On a population basis it may be that the harms of PSA testing and aggressive cancer treatment outweigh the benefits, but on an individual patient basis, if you are one who didn’t get tested and ended up with a fatal cancer, that is a very high price to pay.

A new study from Scandinavia shows the dangers of this approach.  About 700 men who had early detection of cancer were assigned to either watchful waiting, in which they were monitored for any signs the cancer was becoming more aggressive, or to treatment by removal of the prostate.  The follow-up period was over 23 years.  In that time, 63 of the men in the surgery group and 99 in the watchful waiting group died of prostate cancer.  The benefit was obviously greatest in men whose cancer was detected at a younger age and those who had a lower-risk cancer upon detection, but all groups had lower death rates due to prostate cancer after surgery.  The difference is quite significant and physicians will be hard pressed in many cases to now recommend watchful waiting.  The primary issue is that is currently no good wait to determine which cancers will become more aggressive or without almost daily testing, to determine when a cancer begins to change.  The message is pretty clear, if you want to lower your risk of serious prostate cancer and of death from that cancer, get tested regularly and take prompt action once the cancer is detected.