The value of postmastectomy radiotherapy (PMRT) for pathological node-positive triple-negative breast cancers (TNBC) remains debatable. The aim of this population-based retrospective study was to evaluate the effect of PMRT on survival outcomes in this population. Patients diagnosed with stage T1-4N1-N3M0 TNBC between 2010 and 2014 were identified from the Surveillance, Epidemiology, and End Results (SEER) database. We used univariate and multivariate Cox regression hazards method to determine the independent prognostic factors associated with 3-year breast cancer-specific survival (BCSS). The effect of PMRT on 3-year BCSS was analyzed after stratification by pathological staging of groups. Of the 4398 patients included in this study, 2649 (60.2%) received PMRT. Younger age, black ethnicity, and advanced tumor (T) and nodal (N) stage were the independent predictors associated with PMRT receipt (all P < 0.05). Patients who received PMRT showed better 3-year BCSS (OR = 0.720, 95% CI = 0.642–0.808, P < 0.001) than those that did not. The effect of PMRT on 3-year BCSS was analyzed after stratification by pathological staging of groups. The results showed that PMRT was associated with better 3-year BCSS in patients with stage T3–4N1 (P = 0.042), T1-4N2 (P < 0.001), and T1-4N3 (P < 0.001), while comparable 3-year BCSS was found between the PMRT and non-PMRT cohorts with T1–2N1 disease (P = 0.191). Radiotherapy achieved better 3-year BCSS in TNBC patients with stage T3–4N1 and T1-4N2–3 disease. However, no survival benefit was found with the addition of PMRT in patients with T1–2N1 TNBC.

中文翻译：

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乳房切除术后放疗在淋巴结阳性三阴性乳腺癌中的作用

乳房切除术后放疗（PMRT）对于病理性淋巴结阳性三阴性乳腺癌（TNBC）的价值仍有待商bat。这项基于人群的回顾性研究的目的是评估PMRT对该人群生存结果的影响。从监测，流行病学和最终结果（SEER）数据库中识别出2010年至2014年之间被诊断为T1-4N1-N3M0期TNBC的患者。我们使用单因素和多因素Cox回归危险度方法来确定与3年乳腺癌特异性生存率（BCSS）相关的独立预后因素。通过分组病理分期，分析了PMRT对3年期BCSS的影响。在这项研究的4398名患者中，有2649名（60.2％）接受了PMRT。年龄较小，黑人，晚期（T）和淋巴结（N）分期是与PMRT接受相关的独立预测因子（所有P <0.05）。接受PMRT的患者比未接受3年的BCSS更好（OR = 0.720，95％CI = 0.642–0.808，P <0.001）。通过分组病理分期，分析了PMRT对3年期BCSS的影响。结果表明，在T3–4N1期（P = 0.042），T1-4N2（P <0.001）和T1-4N3（P <0.001）的患者中，PMRT与3年期BCSS更好相关，而3年期相当在患有T1–2N1疾病的PMRT和非PMRT队列之间发现了BCSS（P = 0.191）。在患有T3–4N1和T1-4N2–3期的TNBC患者中，放射治疗取得了更好的3年BCSS。然而，在T1-2N1 TNBC患者中，添加PMRT并没有发现生存优势。