Ductal carcinoma of the breast is different from breast cancer, which is one of the types of breast cancer. Ductal carcinoma is a malignant tumor that occurs in the ductal epithelium and is the most common type of breast cancer, accounting for about 70% of all breast cancer patients. There are two types of ductal carcinoma: intraductal carcinoma and ductal infiltrating carcinoma, and patients with intraductal carcinoma have a better prognosis. Ductal carcinoma is generally guided by intraductal carcinoma, which is a type of carcinoma in situ and is treated mainly by surgical excision, often without adjuvant radiotherapy and chemotherapy after surgery. For breast cancer patients, postoperative adjuvant therapy may be required depending on the patient’s pathological stage. The prognosis of patients with intraductal carcinoma is better, while the prognosis of patients with breast cancer is related to the pathological stage.