RT Book, Section A1 Flanagan, Meghan A1 Chen, Yunn-Yi A1 Hwang, E. Shelley A2 Morita, Shane Y. A2 Balch, Charles M. A2 Klimberg, V. Suzanne A2 Pawlik, Timothy M. A2 Posner, Mitchell C. A2 Tanabe, Kenneth K. SR Print(0) ID 1145760168 T1 Ductal Carcinoma in Situ T2 Textbook of Complex General Surgical Oncology YR 2018 FD 2018 PB McGraw-Hill Education PP New York, NY SN 9780071793315 LK accesssurgery.mhmedical.com/content.aspx?aid=1145760168 RD 2024/04/16 AB Ductal carcinoma in situ (DCIS) is a preinvasive clinical diagnosis that lies in the continuum between epithelial atypia and invasive cancer. Although it has been recognized and treated for almost three decades, much remains controversial about this disease and its optimal treatment. The incidence of DCIS has increased significantly since it was first described, largely as a consequence of widespread mammographic screening. Accordingly the presentation pattern has changed from a predominantly palpable lesion to one whose first indication is that of an incidentally discovered mammographic abnormality on routine screening examination. Because DCIS is a preinvasive condition with heterogenous potential for invasion, there remains ongoing debate over whether the current treatment recommendations represent overtreatment of some DCIS which may have never resulted in clinical consequences during a patient’s lifetime. This chapter reviews the epidemiology, diagnosis, and treatment of DCIS as well as some future directions for clinical management of the disease.