The incidence of ductal carcinoma in situ (DCIS) has increased because of increasing use of sensitive imaging modalities. MRI is commonly used for the detection of breast cancer but has not yet been validated in randomized trials. There have not been randomized trials addressing optimal margins of excision or axillary sampling. Whole breast radiation after lumpectomy decreases the risk of recurrence but may be omitted in selected patients. Adjuvant Tamoxifen reduces the risk of recurrence but has no impact on overall survival rates. J. Surg. Oncol. 2012; 105:212–220. © 2011 Wiley Periodicals, Inc.