In BRCA1, breast cancer showed the highest cumulative risk at 72.5% (95% CI, 20.4%-90.5%) followed by ovarian cancer at 65.6% (95% CI, 12.8%-86.4%), gastric cancer at 21.3% (95% CI, 6.9%-33.4%), pancreatic cancer at 16.0% (95% CI, −3.9% to 32.1%), and biliary tract cancer at 11.2% (95% CI, −1.1% to 22.1%). This evidence concerns the gene BRCA1 and breast cancer.