Updates in the Evaluation and Management of Breast Cancer.

Breast cancer is the most commonly diagnosed cancer worldwide. More than 200,000 new cases of invasive breast cancer are diagnosed annually in the United States; approximately 40,000 patients die of the disease. The etiology of most breast cancer cases is unknown, although multiple factors predisposing to the disease have been identified. Apart from increasing age and female sex, these other factors account for only a minority of breast cancer diagnoses. This article provides an overview of the management of noninvasive and invasive breast cancer, which is often complex and varies according to patient factors, disease stage, and breast cancer subtype. Although much progress has been made, continued research endeavors are ongoing; enrollment of eligible patients in prospective clinical trials is an essential way to improve patient outcomes.