The likelihood of recurrence after total excision of stage 0 breast cancer in situ, i.e., ductal carcinoma in situ, is relatively low. Ductal carcinoma in situ is stage 0 breast cancer, which means that the cancer cells are confined to the ducts, have not broken through the basement membrane, and will not spread and metastasize. The prognosis of ductal carcinoma in situ is very good. The cure rate of ductal carcinoma in situ treated by mastectomy can be up to 98%-100%, and the recurrence rate after total mastectomy is less than 0.75%. However, as long as it is a malignant tumor, there is a certain possibility of recurrence. For patients with ductal carcinoma in situ, hormone testing is usually done after surgery for additional treatment. If the patient is found to have hormone ER or PR positive receptor, hormone inhibitor treatment can be performed to reduce the stimulation of hormones to the body and reduce the risk of the patient getting cancer twice. Patients with ductal carcinoma in situ are advised to have regular outpatient follow-up breast ultrasound or mammogram after surgery, and complete breast MRI if necessary.