The effectiveness of screening for prostate cancer - A nested case-control study

Background: Screening for prostate cancer is done commonly in clinical practice, using prostate-specific antigen (PSA) tests or digital rectal examination (DRE). Evidence is lacking, however, to confirm a survival benefit among screened patients. We evaluated the effectiveness of PSA, with or without DRE, in reducing mortality. Methods: We conducted a multicenter nested case-control study at 10 Veterans Affairs medical centers in New England. Among 71661 patients receiving ambulatory care between 1989 and 1990, 501 case patients were identified as men who were diagnosed as having adenocarcinoma of the prostate from 1991 through 1995 and who died sometime between 1991 and 1999. Control patients were men who were alive at the time the corresponding case patient had died, matched (1: 1 ratio) for age and Veterans Affairs facility. The exposure variable (determined blind to case-control status) was whether PSA testing or DRE was performed for screening prior to the diagnosis of prostate cancer among case patients, with the same time interval for control patients. The association of screening and overall or cause-specific (prostate cancer) mortality was adjusted for race and comorbidity. Results: A benefit of screening was not found in our primary analysis assessing PSA screening and all-cause mortality (adjusted odds ratio, 1.08; 95% confidence interval, 0.71-1.64; P=.72), nor in a secondary analysis of PSA and/or DRE screening and cause-specific mortality (adjusted odds ratio, 1.13; 95% confidence interval, 0.63-2.06; P=.68). Conclusions: These results do not suggest that screening with PSA or DRE is effective in reducing mortality. Recommendations for obtaining "verbal informed consent" from men regarding such screening should continue.