Increased risk of male cancer and identification of a potential prostate cancer cluster region in BRCA2

BACKGROUND: The risk of cancer in men from BRCA1 and BRCA2 families is relevant to define to motivate genetic testing and optimize recommendations for surveillance. MATERIAL AND METHODS: We assessed the risk of cancer in male mutation carriers and their first-degree relatives in 290 BRCA1 and BRCA2 families with comparison to matched controls with the aim to motivate genetic testing and optimize recommendations for surveillance. RESULTS: Mutation carriers in BRCA1 families were not at increased risk of cancer, whereas mutation carriers in BRCA2 families were at increased risk of male breast cancer and prostate cancer with cumulative risks of 12.5% and 18.8%, respectively. Breast cancer developed at a mean age of 59 years, typically as ER/PR positive ductal carcinomas. Prostate cancer developed at a mean age of 68 years, with Gleason scores ≥ 8 in 40% of the tumors. The hazard ratio for BRCA2-associated prostate cancer was 3.7 (p < 0.001) in mutation carriers and 3.1 (p = 0.001) in first-degree relatives. Of the 37 prostate cancers, 19 were linked to four BRCA2 mutations within a region defined by c.6373-c.6492. Individuals with mutations herein had a HR of 3.7 for prostate cancer compared to individuals with mutations outside of this region. CONCLUSIONS: Male mutation carriers and first-degree relatives in BRCA2 families are at an increased risk of breast cancer and prostate cancer with a potential prostate cancer cluster region within exon 11 of BRCA2.