Supplementary Material for: Retrospective study of treatment patterns and natural history of patients with T1a/b N0 TNBCs—A single-institution experience.

Introduction: T1a/b, node-negative (node-), triple-negative breast cancers (TNBCs) are underrepresented in randomized drug-approving clinical trials. Given their low incidence, the clinicopathological features, natural history, and treatment patterns of these tumors remain insufficiently understood. Methods: We conducted a single-institution retrospective cohort study of patients with T1a/b, N0, M0 TNBCs. Deidentified patient- and tumor-related data were collected and summarized. Kruskal-Wallis, chi-square, or Fisher exact tests were used to evaluate associations of interest. Kaplan-Meier methods, log-rank tests, and Cox's proportional hazards models were applied for survival analyses. Results: Of 108 cases of node- TNBCs measuring ≤2 cm, 34 node- T1a/b tumors were included in our analysis. All cases had an intermediate to high histological grade, and most had a Ki-67 score of ≥20%. All patients received adjuvant chemotherapy, and many underwent mastectomy (47%). Docetaxel combined with cyclophosphamide was the most common adjuvant chemotherapy regimen (75%). We did not observe significant associations between improved outcomes and treatment with anthracycline-containing regimens. Among patients with node- pT1a/b tumors, the estimated 3-year recurrence-free survival and distant recurrence-free survival rates were both 96.3% (95% CI, 76.5-99.5), and the overall survival rate was estimated to be 100% (95% CI, 100-100). There were no cases of local recurrences observed. Discussion/Conclusions: In our cohort, all patients with T1a/b node- TNBCs were treated with adjuvant chemotherapy and had favorable outcomes even when treated with anthracycline-sparing regimens.

引言：T1a/b期、淋巴结阴性（node-negative）三阴性乳腺癌（triple-negative breast cancers, TNBC）在获批药物的随机对照临床试验中代表性不足。鉴于此类肿瘤发病率较低，其临床病理特征、自然病程及治疗模式迄今尚未得到充分阐明。方法：本研究针对T1a/b、N0、M0型三阴性乳腺癌患者开展单中心回顾性队列研究。收集并汇总去标识化的患者及肿瘤相关数据，采用克拉斯卡尔-沃利斯检验、卡方检验或费舍尔精确检验评估目标关联；采用卡普兰-迈耶法、对数秩检验及考克斯比例风险模型进行生存分析。结果：在108例直径≤2 cm的淋巴结阴性三阴性乳腺癌病例中，共纳入34例淋巴结阴性T1a/b期肿瘤进行分析。所有病例均为中至高组织学分级，多数患者Ki-67指数≥20%。所有患者均接受辅助化疗，近半数（47%）患者行乳房切除术。多西他赛联合环磷酰胺是最常用的辅助化疗方案（75%）。未观察到含蒽环类药物的治疗方案与预后改善存在显著关联。在淋巴结阴性pT1a/b期肿瘤患者中，预估3年无复发生存率及无远处复发生存率均为96.3%（95%置信区间：76.5~99.5），总生存率预估为100%（95%置信区间：100~100），未观察到局部复发病例。讨论/结论：本队列中所有T1a/b期淋巴结阴性三阴性乳腺癌患者均接受了辅助化疗，即便采用避蒽环类治疗方案，仍获得了良好的预后。