BRCA1 and breast cancer: Risk factors for breast cancer include age, genetic mutations (BRCA1 and BRCA2), younger age at menarche, first pregnancy after age 30, nulliparity, older age at menopause, physical inactivity, obesity, dense breast tissue, hormone replacement therapy, oral contraceptives, personal history of breast cancer or other breast diseases, family history of breast cancer, previous radiation therapy, and increased alcohol use [2].