BRCA1 and breast cancer: In the etiology of breast cancer data on risk factors such as: age (the increase of the incidence after 30 years), body mass index (the risk increases after menopause), the family history related to BRCA1 or BRCA2 (5% of all cancers), hormonal factors (early menarche before age 12, late menopause after 55 years, no pregnancy or late pregnancies after age 30, oral contraceptives, lack of breastfeeding), family history of breast cancer, exposure to radiation, and hormone replacement therapy for menopause are very old.