Breast-conserving surgery versus modified radical mastectomy in T1-2N3M0 stage breast cancer: a propensity score matching analysis.

ABSTRACT

PURPOSE: Breast-conserving surgery (BCS) plus radiotherapy and mastectomy exhibit highly comparable prognoses for early-stage breast cancer; however, the safety of BCS for T1-2N3M0 breast cancer remains unclear. This study compared long-term survival for BCS versus (vs.) modified radical mastectomy (MRM) among patients with T1-2N3M0 breast cancer. METHODS: Data of patients with T1-2N3M0 breast cancer were extracted from the Surveillance, Epidemiology, and End Results database. Eligible patients were divided into 2 groups, BCS and MRM; Pearson's chi-squared test was used to estimate differences in clinicopathological features. Propensity score matching (PSM) was used to balance baseline characteristics. Univariate and multivariate analyses were performed to investigate the effects of surgical methods and other factors on breast cancer-specific survival (BCSS) and overall survival (OS). RESULTS: In total, 2124 patients were included; after PSM, 596 patients were allocated to each group. BCS exhibited the same 5-year BCSS (77.9% vs. 77.7%; P = 0.814) and OS (76.1% vs. 74.6%; P = 0.862) as MRM in the matched cohorts. Multivariate survival analysis revealed that BCS had the same BCSS and OS as MRM (hazard ratios [HR] 0.899 [95% confidence intervals (CI) 0.697-1.160], P = 0.413 and HR 0.858 [95% CI 0.675-1.089], P = 0.208, respectively); this was also seen in most subgroups. BCS demonstrated better BCSS (HR 0.558 [95% CI 0.335-0.929]; P = 0.025) and OS (HR 0.605 [95% CI 0.377-0.972]; P = 0.038) than MRM in those with the triple-negative subtype. CONCLUSIONS: BCS has the same long-term survival as MRM in T1-2N3M0 breast cancer and may be a better choice for triple-negative breast cancer.