Breast cancer patients are staged for disease prior to surgery by fine needle aspiration of the axillary lymph nodes or biopsy of the anterior lymph nodes to draw up a surgical plan and mark the surgical area by wire localization. Breast cancer patients may face surgery including breast conservation, mastectomy, breast reconstruction, and axillary lymph node dissection. I Axillary lymph node fine-needle aspiration Axillary lymph node ultrasound-guided FNA or biopsy criteria include: lymph node cortex >2 or 3 mm, loss of fatty nuclei, and asymmetric cortical expansion. Second-line localization of DCIS and many small cancer foci are often not easily identified, and the physician should mark these patients for localization, which can be done by ultrasound-guided directional placement of a localization wire within the tumor. The location of the tumor should be marked on the skin and the patient should be allowed to maintain the same position during the procedure as during imaging, and the precise distance of the tumor under the skin should be recorded. III Sentinel lymph node biopsy Sentinel lymph node biopsy has been used as a standard procedure for breast cancer patients with ultrasound-negative axillary lymph nodes and can provide accurate staging information. SLN is performed by injecting a radioactive tracer in or near the tumor to show lymphatic infiltration. The first lymph node reached by the tracer should be removed, usually 3 lymph nodes are taken and removal of more than 3 anterior lymph nodes no longer increases the diagnostic accuracy. Sentinel lymph node biopsy IV Breast-conserving BCT is also known as mastectomy or wide excision. A locally excised tumor sample is combined with an anterior lymph node biopsy for tumor staging. Breast-conserving BCT has 3 types of postoperative margins: R0 excision – clean margins. Non-point residual – residual <4 mm. Non-point residual - residual >4 mm. Tumor margin classification and corresponding management V. Mastectomy Mastectomy includes 3 types: 1. Simple mastectomy: removal of the entire breast and some axillary lymph nodes near the breast. lymph nodes near the breast. Modified radical mastectomy: the whole breast, most or even all of the axillary lymph nodes, and the pectoralis fascia are removed, and the pectoralis muscle is preserved. 3.Mastectomy with nipple and areola preservation: Most mastectomies remove the nipple, but it can be preserved in the following cases – tumor >2 cm from the nipple, tumor size <5 cm, non-multifocal, and negative axillary lymph nodes. Mastectomy with modified radical mastectomy VI Breast reconstruction Direct reconstruction: implantation of prosthesis. DIEP-flap: deep penetrating branch flap graft of the inferior abdominal wall artery for breast reconstruction, with a DIEP flap graft from the abdomen for breast reconstruction, commonly used. SGAP flap: supra-gluteal artery-penetrating flap grafting for breast reconstruction, used when the patient is unable to perform DIEP-flap due to insufficient abdominal flaps or a history of previous abdominal surgery. TRAM flap: Transverse rectus abdominis muscle flap grafting for breast reconstruction, without altering the blood supply of the flap, through a subcutaneous tunnel. Level I: Axillary group, lateral to the pectoralis minor muscle, including the lateral mammary group, central group, subscapular group and axillary vein lymph nodes, and the lymph nodes between the pectoralis major and minor muscles. Level II: Mid-axillary group, axillary vein lymph nodes on the deep surface of the pectoralis minor muscle. Level III: supra-axillary group, lymph nodes of the subclavian vein on the medial side of the pectoralis minor muscle. ALND of axillary lymph nodes will clear both group I and II lymph nodes. With the advancement of technology, surgeons now try to avoid using ALND by clearing the anterior lymph nodes or by descending the axilla with neoadjuvant therapy, and then use ALND when neoadjuvant therapy is not feasible or when many lymph nodes have metastasized.