Ductal Carcinoma In Situ (DCIS) is a non-invasive breast cancer that starts in the milk ducts. In this condition, abnormal cells are found in the lining of the ducts but have not spread to surrounding breast tissue. DCIS is often detected through mammograms and is considered an early stage of breast cancer. Treatment for DCIS typically involves surgery, such as a lumpectomy or mastectomy, and may include radiation therapy. While DCIS is not life-threatening, it can increase the risk of developing invasive breast cancer in the future, making monitoring and treatment important for affected individuals.