Prospective Cohort Study of Local Recurrence After Radical Breast Cancer Resection

This is a single-center, prospective, non-interventional cohort study. It aims to analyze the clinicopathological characteristics of female patients with isolated local recurrence without distant metastasis after radical breast cancer surgery, identify independent prognostic risk factors affecting progression-free survival (PFS) and overall survival (OS), compare the clinical features and long-term prognostic differences between patients with local recurrence after breast-conserving surgery and those after total mastectomy, and explore eligible populations and optimal individualized treatment strategies after local recurrence. Female patients treated at the Department of Breast Surgery, Jiangsu Provincial People's Hospital, aged ≥18 years, pathologically confirmed to have postoperative local breast cancer recurrence without distant metastasis, tolerant to anti-tumor therapy and capable of completing full follow-up will be consecutively enrolled, and all subjects will sign informed consent forms. Baseline demographic data, primary clinicopathological information, initial surgical and adjuvant treatment records, characteristics of recurrent lesions, and comprehensive treatment data after local recurrence will be uniformly collected to establish a standardized electronic database with double-data entry for quality control. Standardized follow-up of at least 3 years will be conducted starting from the date of confirmed local recurrence, mainly through outpatient reexaminations supplemented by telephone and WeChat follow-up. Endpoint events including secondary local recurrence, distant metastasis, all-cause death and treatment-related adverse reactions will be recorded. Statistical analyses will be performed using SPSS 26.0 and R 4.3.0. Kaplan-Meier survival analysis and the Log-rank test will be adopted for univariate prognostic comparison. Multivariate Cox regression and Logistic regression models will be constructed to screen independent influencing factors. Subgroup and interaction analyses will be carried out stratified by initial surgical modality, molecular subtype, recurrence interval and lesion size. A prognostic nomogram prediction model will be developed based on regression models, with its discrimination and calibration validated. This study will not interfere with routine clinical treatment regimens; all patients will receive treatment in accordance with domestic breast cancer guidelines and institutional MDT standards. All research data will be anonymized throughout the study. After follow-up completion, data will be locked uniformly, and multiple imputation and sensitivity analyses will be performed to ensure robust results. The findings of this study can provide prospective evidence for risk stratification, prognostic assessment and the formulation of individualized treatment regimens for breast cancer patients with postoperative local recurrence.