The risks for breast and ovarian cancers in female relatives of BRCA1 carriers were significantly higher than the risks in female relatives of non-carriers (breast cancer: RR = 4.29, 95% CI = 3.50-5.27; P < 0.001 and ovarian cancer: RR = 21.95, 95% = CI 13.73-35.07; P < 0.001). Here, BRCA1 is linked to breast carcinoma.