In the cancer cohort of 2,665 cases, we identified 74 BRCA pathogenic variants, 31 in BRCA1 with 40 carriers (2.1% in 1,880 cases) and 43 in BRCA2 with 61 carriers (2.5% in 2,417 cases), resulting in the prevalence of 3.8% in the Taiwanese cancer cohort of breast/ovarian cancer. This evidence concerns the gene BRCA1 and cancer.