Family history of prostate and breast cancer and the risk of prostate cancer in the PSA era

BACKGROUND. A family history of prostate cancer (PCa) or breast cancer (BCa) has been associated with the risk of PCa, but the risks were inconsistent in terms of the affected family members, and data in the PSA era are limited. METHODS. This study included a subcohort of the Health Professionals Follow-Up Study composed of a highly PSA screened population from 1986 to 2004 with 3,695 PCa cases identified. Questionnaires and a food frequency questionnaire were administered every other and every 4 years, respectively. Family history of PCa and BCa was ascertained in 1990,1992, and 1996. All statistics were two-sided. RESULTS. A family history of PCa in both a father and brother(s), was associated with a 2.3-fold increased risk of PCa [95% confidence interval (CI) = 1.76-3.12]. Men with a father or brother(s) with a PCa diagnosis at age < 60 and >= 60 had 2.16- and 1.95-fold increased risk of PCa, respectively. A family history of PCa was related to early-onset PCa (< 65 years: RR=2.25, 95% CI=1.95-2.60) and weakly to late-onset PCa (>= 65 years: RR=1.67, 95% CI = 1.52-1.85). History of BCa in a mother or a sister was associated with a 1.22-fold increased risk of PCa (95% CI=1.08-1.38). CONCLUSION. A family history of PCa or BCa significantly increases PCa risk. These associations are evident in a population with widespread PSA screening.