BRCA1 and cancer: Hence, strategies targeting cell nonautonomous oestrogen pathways (i.e. selective oestrogen receptor modulators like tamoxifen or aromatase inhibitors), although successful for primary prevention and adjuvant treatment in oestrogen receptor-positive cancers (Cuzick et al., 2015, Cuzick et al., 2014, Forbes et al., 2008), are unlikely to be successful in BRCA1-mutation carriers.