Ductal Carcinoma in Situ (DCIS)

Ductal carcinoma in situ (DCIS) is noninvasive intraductal carcinoma of the breast and is defined as a malignant proliferation of ductal epithelial cells that are confined to the milk ducts. It is a nonobligate precursor of invasive breast cancer, but at present, there is no reliable method of predicting which lesions will invade in a given time frame. Historically, DCIS was an uncommon lesion; however, widespread use of screening mammography has resulted in a significant increase in the rate of detection, and DCIS now accounts for about 20% of all breast cancers in the United States. Current treatment options for DCIS include breast-conserving surgery (BCS) alone, BCS with radiotherapy (RT), BCS with endocrine therapy, BCS with both RT and endocrine therapy, mastectomy, and even bilateral mastectomy. There is currently concern about overtreatment of this lesion, but there are no reliable data regarding outcomes without treatment. Although survival is excellent with all standard treatments, local recurrence rates vary widely with various treatment options. Given the variety of options available, the goal of treatment is to tailor the management plan to the individual and optimize t