FAMILY HISTORY AND PROSTATE-CANCER RISK IN BLACK, WHITE, AND ASIAN MEN IN THE UNITED-STATES AND CANADA

Increased risk of prostate cancer in men with a family history of the disease has been observed consistently in epidemiologic studies. Howev er, most studies have been confined to white men; little is known abou t familiar aggregation of prostate cancer in populations with unusuall y high incidence, such as African Americans, or in populations with lo w incidence, such as Asian-Americans. The authors report results from a population-based case-control study of prostate cancer among blacks, whites, and Asian-Americans in the United States and Canada. Controls were matched to cases on age (5-year groups), ethnicity (black, white , Chinese-American, Japanese-American), and region of residence (Los A ngeles, San Francisco, Hawaii, Vancouver, Toronto). In the combined gr oup of participants, 5% of controls and 13% of cases reported a father , brother, or son with prostate cancer. These prevalences were somewha t lower among Asian-Americans than among blacks or whiles. A positive family history was associated with a statistically significant two- to threefold increase in risk in each of the three ethnic groups. The ov erall odds ratio associated with such a family history, adjusted for a ge and ethnicity, was 2.5 (95% confidence interval 1.9-3.3). This odds ratio varied by neither ethnicity nor age of the participants. Sera f rom 1,087 controls were used to examine the relations between family h istory and serum concentrations of androgens and prostate-specific ant igen. The concentrations of sex hormone-binding globulin were slightly higher in men with than without a positive family history. Prostate-s pecific antigen concentrations were unrelated to family history.