BRCA1 and cancer: Thirty women had 31 breast cancer diagnoses; 27 cancers were associated to BRCA1, 4 were associated to BRCA2. Also, 25 breast cancers were observed in women under surveillance, while 1.79 were the number expected, resulting in a SIR of 14.0 (95% CI, 9.46–20.7; Table 2).