Screening by prostate-specific antigen and digital rectal examination in relation to prostate cancer mortality: a case-control study

BACKGROUND: The potential role of prostate cancer screening in reducing mortality is uncertain. To examine whether screening with the prostate-specific antigen (PSA) test or digital rectal examination is associated with reduced prostate cancer mortality, we conducted a population-based case-control study in 4 health maintenance organizations. METHODS: Cases were 769 health plan members who died because of prostate adenocarcinoma during the years 1997-2001. We randomly selected 929 controls from the health plan membership and matched them to cases on health plan, age, race, and membership history. Medical records were used to document all screening tests in the 10 years before and including the date on which prostate cancer was first suspected. RESULTS: Among white participants, 62% of cases and 69% of controls had a least 1 screening PSA test or digital rectal examination (odds ratio = 0.73; 95% confidence interval = 0.55-0.97). The corresponding proportions for blacks were 59% and 61% (1.0; 0.59-1.4). Most screening tests were digital rectal examinations; therefore, in the subgroup with no history of PSA screening, the association between digital rectal screening and prostate cancer mortality was similar to the overall association (0.65 [0.48-0.88] among whites; 0.86 [0.53-1.4] among blacks). Very few men received screening PSA without screening digital rectal examination (6% of cases and 7% of controls among whites). CONCLUSIONS: Digital rectal screening was associated with a reduced risk of death due to prostate cancer in our population. Because of several data limitations, this study could not accurately estimate the effect of PSA screening separate from digital rectal examination.