Clinical efficacy and prognosis of adjuvant radiotherapy after breast-conserving surgery for stage Ⅰ-Ⅱ breast cancer / 中华放射肿瘤学杂志

ABSTRACT

Objective To evaluate the clinical efficacy and analyze the prognostic factors of radiotherapy after breast-conserving surgery for stage Ⅰ-Ⅱ breast cancer patients.Methods Clinical efficacy of adjuvant radiotherapy in 1 376 patients with stage Ⅰ and Ⅱ (T1-2 N0-1 M0/T3NoM0) breast cancer after undergoing unilateral breast-conserving surgery between 1999 and 2013 was retrospectively reviewed.Among them,930 patients (67.6％) received radiotherapy combined with chemotherapy including 517 receiving radiotherapy followed by chemotherapy and 413 receiving chemotherapy followed by radiotherapy.In total,1 055 patients (76.7％) were treated with endocrine therapy.Eighty-six patients (39.6％) positive for HER-2 received targeted therapy.The overall survival (OS) and disease-free survival (DFS) rates were calculated using the Kaplan-Meier method.Univariate analysis was performed by Log-rank test and multivariate analysis was conducted by Cox regression method.Results The median follow-up time was 55 months.The quantity of patients receiving follow-up for ≥ 10 years was 90.The 5-and 10-year OS rates for all patients were 98.6％ and 91.5％,and 94.6％ and 82.8％ for 5-and 10-year DFS rates.Mutivariate analysis revealed that age (P=0.016),T staging (P =0.006),N staging (P =0.004),lymphovascular invasion (P =0.038) and time interval between radiotherapy and surgery (P=0.048) were independent prognostic factors for DFS rate.Multivariate analysis demonstrated that N staging (P=0.044) and ER (P=0.026) were independent prognostic factors for DFS in the radiotherapy alone group.Conclusions The radiotherapy-based comprehensive treatment yields favorable clinical outcomes for stage Ⅰ-Ⅱ breast cancer patients after undergoing breast conserving surgery.The prognostic factors for DFS include age,T staging,N staging,lymphovascular invasion and the time interval between radiotherapy and breast-conserving surgery.In the radiotherapy alone group,DFS rate is associated with N staging and ER level.