Abstract 2543: A family affair: Prostate cancer risk and family history of breast or prostate cancer

Abstract

Abstract Background - There is suggestive evidence of familial clustering of breast and prostate cancer in first-degree relatives; women with a family history of prostate cancer are at increased risk of breast cancer. Few studies have investigated joint family history of breast and prostate cancer and prostate cancer risk, and no study to date has examined lethal prostate cancer. Methods - We studied 42,672 from the Health Professionals Follow-up Study between 1996 to 2012. During follow-up, 4,258 prostate cancer cases were diagnosed, of whom 380 were lethal disease. Men self-reported family history of breast and prostate cancer, including in siblings or parents. Using cause-specific hazards regression, we estimated hazard ratios (HR) and 95% confidence intervals (CI) of the association between family history and prostate cancer risk and progression. Results - About 8% of men had a family history of prostate cancer, 8.7% had a family history of breast cancer, and 1.4% of men had a family history of both breast and prostate cancer. A family history of prostate cancer was significantly associated with an increased risk of prostate cancer (HR: 1.69; 95% CI: 1.54-1.85). Increased risk was higher for men with a father diagnosed with prostate cancer (HR: 1.64 95% CI: 1.49-1.80) than for men with a diagnosis in a brother(s) (HR: 1.51 95% CI: 1.27-1.80). A positive family history of breast cancer was associated with a small, but significant 22% increased risk (HR: 1.22; 95% CI: 1.11-1.35). Familial breast cancer in a sister (HR: 1.22 95% CI: 1.06-1.41) increased risk more than familial breast cancer in a mother (HR: 1.12; 95% CI: 0.99-1.25). Men with a family history of both prostate and breast cancer had a 52% (HR: 1.52; 95%CI: 1.23-1.88) increased risk of prostate cancer compared to men with no family history of either cancer. Risk of lethal prostate cancer was also significantly increased for men with a positive family history of prostate cancer (HR: 1.64; 95% CI: 1.20-2.24), as well as for men with a family history of breast cancer (HR: 1.47; 95% CI: 1.07-2.01). Conclusions - These results support the findings of familial aggregation of breast and prostate cancer, and for the first time suggest an association between familial breast cancer and lethal prostate cancer. Data from this prospective study have translational relevance for family counseling of cancer patients. Citation Format: Lauren E. Barber, Travis A. Gerke, Sarah C. Markt, Giovanni Parmigiani, Lorelei A. Mucci. A family affair: Prostate cancer risk and family history of breast or prostate cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2543.