Familial aggregation of prostate cancer in African-Americans and white Americans.

Background: We compared the incidence of prostate cancer in first-degree family members of African-Americans with that in white Americans.

Methods: A historical cohort design was used to enroll 330 incident cases <80 years of age that were diagnosed at the Houston VA Medical Center between June 9, 1993 and June 8, 1996. We compared incidence rates in the probands' families with the incidence rates found in contemporaneous data from the national and regional Surveillance, Epidemiology, and End-Results (SEER) program.

Results: Three-hundred five probands (41% African-American) had evaluable first-degree relatives (394 African-American, 527 non-African-American). The standardized incidence ratio was 1.61 overall (95% confidence interval (CI): 1.22-2.13) and did not differ between African-American and non-African-American families: 1.58 (1.05-2.29) and 1.65 (1.06-2.45) in African-Americans and non-African-Americans, respectively.

Conclusions: The similar level of familial aggregation is evidence that the higher incidence of prostate cancer in African-Americans is not attributable to a higher prevalence of germline mutations predisposing to the disease.