Comparison of treatment outcome between breast-conservation surgery with radiation and total mastectomy without radiation in patients with one to three positive axillary lymph nodes

Purpose: To test the difference in treatment outcome between breast-conservation surgery with radiation and total mastectomy without radiation, to evaluate the benefits of adjuvant radiotherapy in patients with one to three positive axillary lymph nodes. Methods and Materials: Using the Severance Hospital Breast Cancer Registry, we divided the study population of T1, T2 and one to three axillary node-positive patients into two groups: breast-conservation surgery with radiation (BCS/RT) and total mastectomy without radiation (TM/no-RT). Data related to locoregional recurrence, distant recurrence, and death were collected, and survival rates were calculated. Results: The study population consisted of 125 patients treated with BCS/RT and 365 patients treated with TM/no-RT. With a median follow-up of 68.4 months, the 10-year locoregional recurrence-free survival rate with BCS/RT and TM/no-RT was 90.5% and 79.2%, respectively (p = 0.056). The 10-year distant recurrence-free survival rate was 78.8% for patients treated with BCS/RT vs. 68.0% for those treated with TM/no-RT (p = 0.012). The 10-years overall survival rate for patients treated with BCT/RT and TM/no-RT was 87.5% and 73.9%, respectively (p = 0.035). After multivariate analysis, patients treated with BCT/RT had better distant recurrence-free survival (hazard ratio [HR], 0.527; 95% confidence interval [CI], 0.297-0.934; p = 0.028), with improving locoregional recurrence-free survival (HR, 0.491; 95% CI, 0.231-1.041; p = 0.064) and overall survival trend (HR, 0.544; 95% CI, 0.277-1.067; p = 0.076). Conclusions: This study provides additional evidence that adjuvant radiation substantially reduces local recurrence, distant recurrence, and mortality for patients with one to three involved nodes.