Clinical Efficacy and Safety Assessment of Breast-Conserving Surgery for Central Breast Cancer: A Prospective Randomized Controlled Trial

This prospective, open-label, multicenter, randomized clinical trial plans to enroll 158 patients with primary central early-stage breast cancer. Participants will be randomly assigned to two groups: the control group undergoing total mastectomy (with optional prosthetic implantation or autologous tissue reconstruction), and the experimental group receiving breast-conserving surgery with radiotherapy (nipple resection with concurrent nipple reconstruction and oncoplastic surgery when nipple involvement is present; conversion to total mastectomy required for intraoperative or postoperative positive margins). All enrolled patients will initiate surgical treatment within 24 hours after eligibility confirmation. Experimental group patients must complete preoperative breast ultrasound, mammography, and MRI to assess breast-conserving feasibility. All patients receive standardized adjuvant therapy (chemotherapy, endocrine therapy, targeted therapy, and immunotherapy) according to guidelines. Those meeting neoadjuvant therapy criteria may receive preoperative systemic treatments (chemotherapy, endocrine therapy, targeted therapy, and immunotherapy), excluding neoadjuvant radiotherapy. Primary Endpoint: local recurrence rate Secondary Endpoints: disease-free survival (DFS), overall survival (OS), patient-reported outcomes (PRO), and surgery-related complications. Inclusion Criteria: 1. Female patients aged 18-70 years with primary breast cancer; 2. Histopathologically confirmed invasive breast cancer (meeting latest ASCO/CAP guidelines criteria) with: * TNM stage T1-2; * Nodal stage N0-1; 3. Ductal carcinoma in situ (DCIS) with maximum tumor diameter \<3 cm; 4. Paget's disease; 5. Neoadjuvant chemotherapy permitted for eligible patients; 6. Unicentric lesion confirmed by breast ultrasound, mammography, and MRI; 7. Nipple-areolar complex resection required for preoperative imaging or pathologically confirmed nipple involvement; 8. Enrolled patients randomized 1:1 to breast-conserving surgery or total mastectomy group; 9. Participants voluntarily signed informed consent forms and completed ethics review procedures.