Absolute contraindications: (1) previous radiation treatment to the chest wall or breast; (2) patients in pregnancy; (3) diffuse microcalcifications, suspected of malignancy; (4) multiple tumors, which cannot be removed by a single total resection to achieve negative margins; (5) intraoperative resection of specimens with tumor invasion at the cut edge. Relative contraindications: (1) active connective tissue disease (especially scleroderma and lupus); (2) tumors larger than 5 cm; (3) localized tumor invasion on the cut edge of the resected specimen; (4) patients with genetic susceptibility to breast cancer: patients who undergo breast-conserving surgery are more likely to have recurrence in the ipsilateral breast and more likely to have breast cancer in the contralateral breast, so prophylactic bilateral mastectomy is feasible. In addition to the above contraindications, breast-conserving surgery can be considered for patients with breast cancer, but breast-conserving surgery must be followed by radiation therapy.