Risk factors for breast cancer

Breast cancer remains the most common cancer diagnosis and the second leading cause of cancer death in American women. Risk factors for the development of breast cancer include age, reproductive history family history, exogenous and endogenous hormones, and behavioral considerations, such as alcohol consumption and low physical activity. The lifetime risk for a woman to contract breast cancer is estimated to be one in nine, or 12.5% of women. This article is an overview of known and suspected risk factors for breast cancer.