BRCA1 and breast cancer: In a case-control study, in which 20 primary breast cancers diagnosed post-RRSO were matched to 36 breast cancers of BRCA1/2 GPV carriers pre-RRSO, Van Verschuer et al. showed that breast cancers post-RRSO were smaller (11 vs. 17 mm, p < 0.05), with lower mitotic activity index (12 vs. 22 mitotic counts/mm2, p < 0.05) [14].