Ductal carcinoma in situ (DCIS) is the presence of abnormal cells inside a milk duct in the breast. DCIS is considered the earliest form of breast cancer. DCIS is noninvasive, meaning it hasn't spread out of the milk duct to invade other parts of the breast. DCIS is usually found during a mammogram done as part of breast cancer screening or when there is another concern with a woman's breast. Because of increased screening with mammograms, the rate at which DCIS is diagnosed has increased dramatically in recent years. While DCIS isn't life-threatening, it does require treatment to prevent the condition from becoming invasive. Most women with DCIS are effectively treated with breast-conserving surgery and radiation.
Treatment of DCIS has a high likelihood of success, in most instances removing the tumor and preventing any recurrence. In most cases, treatment options for DCIS include: Lumpectomy and radiation therapy Simple mastectomy In some cases, treatment options may include: Lumpectomy only Lumpectomy and the drug tamoxifen