The resection of carcinoma in situ of breast does not prove that it is fine. Although the scope of carcinoma in situ is relatively limited, there is still a certain possibility of recurrence after the surgery, so it is necessary to conduct regular review after the surgery to exclude the possibility of recurrence. Carcinoma in situ is an abnormal proliferation of epithelial cells at the site of disease, and the scope of the lesion has not broken through the basement membrane. After early radical surgery, most of the lesions can be removed completely and achieve the effect of eradication. However, a few patients still have the possibility of recurrence. It is recommended that after the removal of carcinoma in situ, regular breast examination should be conducted to exclude the possibility of recurrence of breast cancer, and when recurrent lesions appear, early detection and treatment should be carried out. It is recommended to go to the hospital for consultation, and the professional physician will analyze the situation according to the patient’s specific condition.