Breast cancer is the most frequently encountered cancer in women today. It is estimated that more than 180,000 women will be diagnosed with breast cancer this year. However, somewhere between 900,000 and 1.8 million women will undergo breast biopsy. The primary care provider will most likely be the first to identify a local problem in the breast and is often the initial source of information regarding diagnosis and treatment. Hundreds of thousands of women are currently undergoing local, as well as systemic treatment for their breast cancer. In addition, a large number of women are living with breast cancer that has metastasized to other organs. It is estimated that the clinical courses for these women ranges from 5–40 years. During this long block of time, the women will work intimately with her oncology center, as well as her primary care provider. In order to provide knowledgeable, comprehensive health care to all women, primary care providers must possess a basic understanding of the risk factors, diagnosis, treatment, and natural history of breast cancer.