Breast-Conserving Therapy is Associated with Better Survival than Mastectomy in Early-Stage Breast Cancer: A Propensity Score Analysis

Abstract

Background: Recent retrospective studies have reported that breast-conserving therapy (BCT) led to improved overall survival (OS) than mastectomy in some populations. We aimed to compare the efficacy of BCT and mastectomy using the SEER database. Methods: Between 2010 and 2015, 99,790 eligible patients were identified. We included early-stage breast cancer patients with 5cm or smaller tumors and three or fewer positive lymph nodes in our study. We compared the OS results among patients with BCT and mastectomy. Kaplan-Meier plots, Cox proportional hazard regressions were used to evaluate the outcomes. Propensity-score matching was used to assemble a cohort of patients with similar baseline characteristics. Results: In our study, 77,452 (77.6%) patients underwent BCT and 22,338 (22.4%) underwent mastectomy. The 5-year OS rate was 94.7% in the BCT group and 87.6% in the mastectomy group (P <0.001). After matching, multivariate analysis in the matched cohort showed that women underwent mastectomy was associated with worse OS results compared with those with BCT (Hazard ratio (HR) = 1.628; 95% confidence intervals (CIs) = 1.445- 1.834, P<0.001). Patients with different subtypes and age group (>50 years old; ≤50 years old) received BCT all showed significantly better OS than those received mastectomy. The effect of surgery choice on survival was the same in matched and all cohorts. Conclusions: Our study showed that BCT was associated with improved survival compared with mastectomy in early-stage breast cancer patients. It seems advisable to encourage patients to receive BCT rather than mastectomy in early-stage patients when feasible and appropriate.

Bilateral mastectomy associated with higher breast cancer mortality among patients with estrogen receptor positive progesterone receptor negative localized breast cancer

“…If such endocrine changes were induced by mastectomy in breast cancer patients, it may be reflected in their long-term outcomes relative to patients undergoing lumpectomy. If such a phenomenon existed, it could help shed light on the curious finding that most retrospective analyses since the previously-mentioned pioneering randomized controlled trials have found improved overall survival or disease-specific survival with lumpectomy and radiation relative to mastectomy (13,(16)(17)(18)(19)(20)(21)(22)(23). A 2013 retrospective analysis from the California Cancer Registry suggested that the discrepancy in overall survival may be related to a higher burden of non-fatal comorbidities among patients undergoing mastectomy relative to lumpectomy with radiation (13).…”