Breast-conserving therapy versus mastectomy for breast cancer: a ten-year follow-up single-center real-world study

BACKGROUND: The rapid development of early diagnostic methods and systematic treatment for breast cancer have shed lights on the insight of prognosis of breast-conserving therapy versus mastectomy. However, there are relatively few studies with long-term follow-up, large patient cohort and under the contemporary setting in China on the subject of survival of patients undergoing breast conserving therapy versus mastectomy. METHODS: Data on the cases of breast-conserving therapy and mastectomy for breast cancer from October 1, 2005 to September 31, 2010 were retrieved from the breast cancer database of Chinese PLA General Hospital. The clinicopathological characteristics of patients were compared by chi-square test or Fisher’s exact test. Breast cancer-specific survival, disease-free survival, local recurrence-free survival, loco-regional recurrence-free survival, and distant metastasis-free survival were calculated and compared by Kaplan-Meier survival analysis and log-rank test firstly. And then Cox Proportional-Hazards model was used for multivariate analysis. RESULTS: There were 296 patients in the breast-conserving surgery group and 675 patients in the mastectomy group. For patients with invasive breast cancer in the entire cohort, the 10-year breast cancer-specific survival rate of patients in the breast-conserving surgery group at stage I-II was significantly higher than that of the mastectomy group. However, surgical method was not an independent prognostic factor for breast cancer-specific survival, disease-free survival and local recurrence-free survival. Moreover, N stage and luminal B-like subtype were independent prognostic factors for the breast cancer-specific survival of invasive breast cancer in the entire cohort. CONCLUSIONS: This study suggests that there is no significant difference in breast cancer-specific survival between breast cancer patients undergoing breast-conserving surgery and mastectomy after adjusting for confounding factors. Lymph node staging is the major risk factor affecting patients’ survival. In this case, choosing patients with smaller tumor size, avoiding patients with stage N3, and removing a smaller volume of breast tissue including tumors while ensuring negative margins may reduce the patient’s risk of local recurrence and loco-regional recurrence.