I. Breast-conserving surgery incision selection Double incision is generally advocated; when the tumor is located in the upper part of the breast, a curved incision parallel to the areola is taken; when the tumor is located in the lower part of the breast, a radial incision is taken with the nipple as the center. The incision of the mass must be directly above the tumor; the incision of the circumareolar areola should not be taken for lesions that are not near the areola; when mastectomy is changed to mastectomy due to positive margins during mass excision, the incision of mastectomy should accommodate the incision of mass excision. Skin excision is not a prerequisite for surgery and it does not improve the effectiveness of the procedure. Figure 1 Selection of breast-conserving surgical incisions Zhang Huiming, Department of General Surgery, Beijing Friendship Hospital II. Scope of breast-conserving surgical excision The tumor should be excised so that it is completely encapsulated in normal fat and or breast tissue. Excision sufficient to reach the amount of tumor free on the naked eye at the edge of the specimen is sufficient. Do not disrupt the skin margins as this will lead to unsatisfactory cosmetic results. It is not necessary to include the pectoralis fascia in the specimen, unless the lesion is close to it. Drainage is placed in the axilla, and no drainage is placed in the mammary incision. In cases requiring axillary clearance, an additional curved incision parallel to the axillary fold line, approximately 5-6 cm long, is made in the axilla. the extent of clearance is the same as that of modified radical surgery, and grade I and II levels are cleared according to Berg’s grading criteria for axillary lymph nodes. Contraindications to breast-conserving surgery 1.Patients who have received moderate or high dose radiation therapy to the breast or chest wall in the past; 2.Patients who need to receive radiation therapy during pregnancy; 3.Mammography shows diffuse suspicious or malignant microcalcifications; 4.Patients with multicenter lesions that cannot be excised through a single incision to achieve negative margins and satisfactory cosmetic results; 5.Patients with positive margins who cannot obtain negative margins even after re-extended excision pathological margins. Active connective tissue diseases involving the skin (especially scleroderma and systemic lupus erythematosus); 7. Tumors larger than 5 cm and focal positive margins; 8. Premenopausal women with known BRCA1/2 mutations.