BRCA2 and breast cancer: The lifetime male breast cancer risks were previously reported to be 2%-6% for BRCA1 and 7%-13% for BRCA2 carriers (Data Supplement).3,6,9-13 We estimated these risks to be somewhat lower, 0.4% (95% CI, 0.1 to 1.5) and 3.8% (95% CI, 1.9 to 7.7), respectively.