BRCA1 and breast cancer: BC risks of female BRCA1/2 PV carriers were found to be affected by a variety of intrinsic and extrinsic factors, such as mammographic density [8, 9], family history of BC and ovarian cancer (OC), variant localization [2], birth cohort [10–12], reproductive history (e.g., age at menarche, first birth, and menopause, number of full-term pregnancies, breastfeeding) [13] and further modifiable factors such as body weight, physical activity, and alcohol consumption [14], among others.