Survival outcomes for breast conserving surgery versus mastectomy among elderly women with breast cancer

Purpose Elderly patients have different physical condition and tumor biology of breast cancer. Surgical choices for older patients are complicated and several studies have reported that breast conserving surgery (BCS) had better survival than mastectomy in different patient population. The major object of this study was to compare the efficacy of BCS and mastectomy in the whole elderly cohort in SEER database.Methods Female patients aged over 70 years old and diagnosed with breast cancer between 2010 and 2015 were included from SEER database. Propensity score matching (PSM) was used to establish a cohort composing of similar characteristics. We compared the overall survival (OS) among patients undergoing BCS and mastectomy. Kaplan-Meier analysis and Cox proportional regression model were used to evaluate the associated factors of survival outcome.Results Of 44755 eligible patients, 30375 (67.9%) patients underwent breast conserving surgery (BCS) and 14380 (32.1%) patients underwent mastectomy. After PSM, 7222 patients in each group were analyzed and there was no significant difference between BCS and mastectomy in terms of the overall survival rate (85.8% in BCS group and 85.0% in mastectomy group, p = 0.135). Multivariable analysis also indicated that no significant difference between two surgical procedures after adjusting for covariates both in all patients (HR = 1.074, 95% CI 0.992-1.105, p = 0.098) and matched cohort (HR = 1.062, 95% CI 0.997-1.132, p = 0.063). Subgroup analysis demonstrated that postoperative radiotherapy and chemotherapy contributed to the survival benefit of BCS compared to mastectomy (p < 0.05).Conclusion For elderly breast cancer patients, BCS and mastectomy had similar overall survival rate. BCS might be a better surgical treatment with or without axillary surgery, radiotherapy and chemotherapy.