“Watchful Waiting” Works Well for Prostate Cancer

“Watchful waiting”, or “active surveillance” is an option for treating certain types of prostate cancer that has grown in importance in recent years.  It must be reserved for men over 65, and those whose cancer is clinically localized.  The concept has received a boost with new study results posted in the Journal of the American Medical Association.

This was the largest study done in the USA since the introduction of prostate-specific antigen (PSA) screening.  It followed 14,500-odd men over 65 diagnosed with stage T1 or T2 prostate cancer between 1992 and 2002 for an average of 8.3 years.  (In stage T1 the tumor is too small to be seen on scans or felt during examination of the prostate - it may have been discovered by needle biopsy, after finding a raised PSA level.  In stage T2 the tumor is completely inside the prostate gland.)   As well as staging, the degree of microscopic differentiation is important; it gives the Gleason score.  Cells which are well differentiated resemble normal prostate cells more closely than those that are completely disorganized, unequal in size and shape, and so on, which are indicative of malignancy.

The 10-year mortality rate for men at an average age of 78 was 8.3% for the men with well-differentiated tumor cells, while for those with moderately differentiated it was 9.1%.  Those with the most disorderly (i.e. poorly differentiated) tumors had a 25.6% 10-year mortality.  These numbers are much better than those from the pre-PSA era – presumably because patients are diagnosed at a much earlier stage compared with 20 years ago.

Will these findings change the advice physicians give their patients?  They have already caused some discussion among experts.  It’s clear they are not valid for men under 60.  The prevailing view is that decisions regarding treatment (or non-treatment) should be individualized.  The only agreement seems to be that aggressive (i.e. poorly differentiated, or spreading) tumors require aggressive treatment.  Further studies of watchful waiting are under way; in the meantime, it seems to be a good alternative option for over 70-year-olds with non-aggressive tumors who want to avoid surgery, chemotherapy, or radiation.  Remember, watchful waiting is not a euphemism for doing nothing, but rather a decision to delay treatment in favor of careful monitoring.