A metaanalysis from 2018, which was based on the last two mentioned studies by Rebbeck et al. 2005 and Kotsopoulos et al. 2018 and included a total of 1100 BRCA1/2-pV carriers, showed no association between HRT and the risk of breast cancer after RRSO (HR 1.01; 95% CI 0.16–1.54) (Marchetti et al. 2018). This evidence concerns the gene BRCA1 and breast cancer.