Two Studies Continue Debate on Prostate Cancer Screening

摘要

Evidence that screening for prostate cancer meets the strict criteria for a valid screening test (see Science Watch Nov/Dec, 2008) has been hard to come by. A systematic review published in 2006 found only two acceptable randomized trials of screening compared with no screening or routine care.The relative risk and confidence interval for mortality then was 1.01 (0.80 -1.29) (D. Ilic, et al., Cochrane Database Syst Rev., 3: CD004720, 2006). Many clinicians, patients, and health economists, among others, will have been hoping that two major trials reported in the March 26, 2009, issue of the New England Journal of Medicine would settle the controversy (paper #10 and G.L. Andriole, et al., 360[13]: 1310-9, 2009, at #11 with total cites 49 and latest count 38).rnAs reported in paper #10, the European Randomized Study of Screening for Prostate Cancer (ERSPC) was conducted in seven countries with some variations in methodology between participating centers. A PSA above 3 or 4 ng/mL was an indication for prostate biopsy. The principal end-point was death from prostate cancer. Cancer was detected in 8.2% of those screened and in 4.8% of controls. For the first six years of follow-up, mortality rates from prostate cancer remained much the same in the two groups, but then a divergence in favor of screening began and the rate ratio for death from prostate cancer was significantly reduced at 0.80. A 20% reduction in prostate cancer mortality sounds important but, put another way, the data mean that 48 additional men would need to be treated to prevent 1 death from cancer of the prostate.