Risk FactorsThe most important risk factor for breast cancer is increasing age. Other established risk factors include personal or family history of breast cancer, history of abnormal breast biopsy, genetic alterations, early age at onset of menses, late age at onset of menopause, never having children or having a first live birth at age 30 or older, and history of exposure to high dose radiation. Associations have also been suggested between breast cancer and oral contraceptives, long-term use of hormone replacement therapy, obesity (in post-menopausal women), alcohol, and a diet high in fat. Some studies suggest that exercise in youth might give life-long protection against breast cancer and that even moderate physical activity as an adult could lower breast cancer risk. More research is needed to confirm these findings.
Related Risk Factors Indicators: