RT Book, Section A1 Lippman, Marc E. A2 Longo, Dan L. SR Print(0) ID 1135229398 T1 Breast Cancer T2 Harrison's Hematology and Oncology, 3e YR 2016 FD 2016 PB McGraw-Hill Education PP New York, NY SN 9781259835834 LK hemonc.mhmedical.com/content.aspx?aid=1135229398 RD 2024/04/19 AB Breast cancer is a malignant proliferation of epithelial cells lining the ducts or lobules of the breast. In the year 2014, about 180,000 cases of invasive breast cancer and 40,000 deaths will occur in the United States. In addition, about 2000 men will be diagnosed with breast cancer. Epithelial malignancies of the breast are the most common cause of cancer in women (excluding skin cancer), accounting for about one-third of all cancer in women. As a result of improved treatment and earlier detection, the mortality rate from breast cancer has begun to decrease very substantially in the United States. This Chapter will not consider rare malignancies presenting in the breast, such as sarcomas and lymphomas, but will focus on the epithelial cancers.