BRCA1 and endometrial cancer: Of the 4893 women studied, 3536 were BRCA1 pathogenic variant carriers, explaining why there was no statistically significant increase in endometrial cancer risk in the BRCA2 group, despite similar SIRs (BRCA1 SIR = 1.91, 95% CI = 1.06–3.19, p = 0.03, BRCA2 SIR = 1.75, 95% CI = 0.55–4.23, p = 0.2).