© Eric Yarnell, ND, May, 2010.
Two large randomized trials published in the New England Journal of Medicine dealt two further devastating blows to the idea of using the total prostate-specific antigen (tPSA) blood test to screen for cancer. I say tPSA to differentiate it from the less-commonly tested free PSA (fPSA) or complexed PSA (cPSA).
In the slightly positive trial, conducted in several countries in Europe, 182,160 men were either tested for tPSA every so often or not and monitored for whether or not they developed prostate cancer. Those who were tested had a 20% decreased rate of death due to prostate cancer after an average of 9 years of follow-up. Unfortunately, this meant that 1,410 men had to be screened and 48 had to be treated (mostly with radical prostatectomy) to save one life from prostate cancer. The expense and adverse effects due to this level of intervention indicates just how ineffective the tPSA screening was in this study. Also, the death rate from all causes did not appear to be decreased by tPSA testing.
In the second study, 76,693 men in the US were either tested for tPSA periodically or not. After between 7-10 years of follow-up, there was no difference in prostate cancer death rates between the two groups. The overall rate of death due to prostate cancer was extremely small, just 94 men.
At this point, with two other clinical trials previously having found the same lack of efficacy of tPSA screening, it seems fair to say this test should be abandoned for most men. The latest guidelines from the American Cancer Society call for men to discuss with their doctors whether to screen. This makes little sense, as most men do not have the background in statistics or research to understand the studies, and presumably their doctors do and should no in most cases the test is ineffective. Men with a close family member who died of prostate cancer before the age of 65 years might still benefit from tPSA screening, but most others will not.
References
Andriole GL, Grubb RL III, Buys SS, et al. Mortality results from a randomized prostate-cancer screening trial. N Engl J Med 2009;360:1310-9.
Schröder FH, Hugosson J, Roobol MJ, et al. Screening and prostate-cancer mortality in a rnadomized European study. N Engl J Med 2009;360:1320-8.