BACKGROUND Whether surgical axillary staging as part of breast-conserving therapy can be omitted without compromising survival has remained unclear. METHODS In this prospective, randomized, noninferiority trial, we investigated the omission of axillary surgery as compared with sentinel-lymph-node biopsy in patients with clinically node-negative invasive breast cancer staged as T1 or T2 (tumor size, ≤5 cm) who were scheduled to undergo breast-conserving surgery. We report here the per-protocol analysis of invasive disease-free survival (the primary efficacy outcome). To show the noninferiority of the omission of axillary surgery, the 5-year invasive disease-free survival rate had to be at least 85%, and the upper limit of the confidence interval for the hazard ratio for invasive disease or death had to be below 1.271. RESULTS A total of 5502 eligible patients (90% with clinical T1 cancer and 79% with pathological T1 cancer) underwent randomization in a 1:4 ratio. The per-protocol population included 4858 patients; 962 were assigned to undergo treatment without axillary surgery (the surgery-omission group), and 3896 to undergo sentinel-lymph-node biopsy (the surgery group). The median follow-up was 73.6 months. The estimated 5-year invasive disease-free survival rate was 91.9% (95% confidence interval [CI], 89.9 to 93.5) among patients in the surgery-omission group and 91.7% (95% CI, 90.8 to 92.6) among patients in the surgery group, with a hazard ratio of 0.91 (95% CI, 0.73 to 1.14), which was below the prespecified noninferiority margin. The analysis of the first primary-outcome events (occurrence or recurrence of invasive disease or death from any cause), which occurred in a total of 525 patients (10.8%), showed apparent differences between the surgery-omission group and the surgery group in the incidence of axillary recurrence (1.0% vs. 0.3%) and death (1.4% vs. 2.4%). The safety analysis indicates that patients in the surgery-omission group had a lower incidence of lymphedema, greater arm mobility, and less pain with movement of the arm or shoulder than patients who underwent sentinel-lymph-node biopsy. CONCLUSIONS In this trial involving patients with clinically node-negative, T1 or T2 invasive breast cancer (90% with clinical T1 cancer and 79% with pathological T1 cancer), omission of surgical axillary staging was noninferior to sentinel-lymph-node biopsy after a median follow-up of 6 years. (Funded by the German Cancer Aid; INSEMA ClinicalTrials.gov number, NCT02466737.).

中文翻译：

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乳腺癌的腋窝手术 - INSEMA 试验的主要结果。


背景 作为保乳治疗的一部分，是否可以在不影响生存率的情况下省略手术腋窝分期仍不清楚。方法 在这项前瞻性、随机、非劣效性试验中，我们调查了在计划接受保乳手术的临床淋巴结阴性浸润性乳腺癌患者中，与前哨淋巴结活检相比，腋窝手术的遗漏情况（肿瘤大小为 ≤5 cm）。我们在这里报告侵袭性无病生存期 （主要疗效结果） 的按方案分析。为了显示省略腋窝手术的非劣效性，5 年侵袭性无病生存率必须至少为 85%，并且侵袭性疾病或死亡风险比的置信区间上限必须低于 1.271。结果 共有 5502 例符合条件的患者 （90% 为临床 T1 癌症，79% 为病理性 T1 癌症） 以 1：4 的比例接受随机分组。符合方案的人群包括 4858 名患者;962 例接受无腋手术治疗 （手术-省略组），3896 例接受前哨淋巴结活检 （手术组）。中位随访时间为 73.6 个月。手术缺失组患者的估计 5 年侵袭性无病生存率为 91.9% （95% 置信区间 [CI]，89.9 至 93.5），手术组患者为 91.7% （95% CI，90.8 至 92.6），风险比为 0.91 （95% CI，0.73 至 1.14），低于预先设定的非劣效性边缘。对共 525 名患者发生的第一个主要结局事件 （侵袭性疾病的发生或复发或任何原因导致的死亡） 的分析 （10.8%），显示手术-不作为组和手术组在腋窝复发发生率 （1.0% vs. 0.3%） 和死亡 （1.4% vs. 2.4%） 方面存在明显差异。安全性分析表明，与接受前哨淋巴结活检的患者相比，手术-省略组患者的淋巴水肿发生率较低，手臂活动度更高，手臂或肩部运动时疼痛减轻。结论 在这项涉及临床淋巴结阴性、T1 或 T2 浸润性乳腺癌患者 （90% 为临床 T1 癌，79% 为病理性 T1 癌） 的试验中，中位随访 6 年后，遗漏手术腋窝分期不劣于前哨淋巴结活检。（由德国癌症援助组织资助;INSEMA ClinicalTrials.gov 编号，NCT02466737.）。