BRCA1 and breast cancer: Non-reproductive risk factors of particular interest for breast cancer include obesity,7 with a doubling of breast cancer risk observed in overweight post-menopausal females, and increased alcohol consumption which is estimated to contribute to approximately 4% of all breast cancer cases diagnosed in 2020.8 Approximately 5–10% of breast cancers have an underlying genetic or hereditary cause such as BRCA1 or BRCA2 mutations, but eight out of nine females who are diagnosed with breast cancer do not have an affected female first degree relative.9