ImportanceData on oncological outcomes after omission of axillary lymph node dissection (ALND) in patients with breast cancer that downstages from node positive to negative with neoadjuvant chemotherapy are sparse. Additionally, the best axillary surgical staging technique in this scenario is unknown.ObjectiveTo investigate oncological outcomes after sentinel lymph node biopsy (SLNB) with dual-tracer mapping or targeted axillary dissection (TAD), which combines SLNB with localization and retrieval of the clipped lymph node.Design, Setting, and ParticipantsIn this multicenter retrospective cohort study that was conducted at 25 centers in 11 countries, 1144 patients with consecutive stage II to III biopsy-proven node-positive breast cancer were included between April 2013 and December 2020. The cumulative incidence rates of axillary, locoregional, and any invasive (locoregional or distant) recurrence were determined by competing risk analysis.ExposureOmission of ALND after SLNB or TAD.Main Outcomes and MeasuresThe primary end points were the 3-year and 5-year rates of any axillary recurrence. Secondary end points included locoregional recurrence, any invasive (locoregional and distant) recurrence, and the number of lymph nodes removed.ResultsA total of 1144 patients (median [IQR] age, 50 [41-59] years; 78 [6.8%] Asian, 105 [9.2%] Black, 102 [8.9%] Hispanic, and 816 [71.0%] White individuals; 666 SLNB [58.2%] and 478 TAD [41.8%]) were included. A total of 1060 patients (93%) had N1 disease, 619 (54%) had ERBB2 (formerly HER2)–positive illness, and 758 (66%) had a breast pathologic complete response. TAD patients were more likely to receive nodal radiation therapy (85% vs 78%; P = .01). The clipped node was successfully retrieved in 97% of TAD cases and 86% of SLNB cases (without localization). The mean (SD) number of sentinel lymph nodes retrieved was 3 (2) vs 4 (2) (P < .001), and the mean (SD) number of total lymph nodes removed was 3.95 (1.97) vs 4.44 (2.04) (P < .001) in the TAD and SLNB groups, respectively. The 5-year rates of any axillary, locoregional, and any invasive recurrence in the entire cohort were 1.0% (95% CI, 0.49%-2.0%), 2.7% (95% CI, 1.6%-4.1%), and 10% (95% CI, 8.3%-13%), respectively. The 3-year cumulative incidence of axillary recurrence did not differ between TAD and SLNB (0.5% vs 0.8%; P = .55).Conclusions and RelevanceThe results of this cohort study showed that axillary recurrence was rare in this setting and was not significantly lower after TAD vs SLNB. These results support omission of ALND in this population.

中文翻译：

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新辅助化疗淋巴结降期后省略腋窝淋巴结清扫

对于通过新辅助化疗从淋巴结阳性降级至阴性的乳腺癌患者，省略腋窝淋巴结清扫术 (ALND) 后的肿瘤学结果数据很少。此外，在这种情况下最佳的腋窝手术分期技术尚不清楚。 目的通过双示踪剂标测或靶向腋窝清扫术（TAD）（将 SLNB 与定位和截取的淋巴液检索相结合）研究前哨淋巴结活检（SLNB）后的肿瘤学结果设计、设置和参与者这项多中心回顾性队列研究在 11 个国家的 25 个中心进行，纳入了 2013 年 4 月至 2020 年 12 月期间连续 II 期至 III 期活检证实淋巴结阳性乳腺癌的 1144 名患者。腋窝、局部区域和任何侵袭性（局部或远处）复发的发生率通过竞争风险分析确定。暴露 SLNB 或 TAD 后遗漏 ALND。主要结果和措施主要终点是任何 3 年和 5 年发生率腋窝复发。次要终点包括局部区域复发、任何侵袭性（局部和远处）复发以及切除的淋巴结数量。 结果 总共 1144 名患者（中位 [IQR] 年龄，50 [41-59] 岁；78 [6.8%] 亚裔患者其中包括 105 名 [9.2%] 黑人、102 名 [8.9%] 西班牙裔和 816 名 [71.0%] 白人；666 名 SLNB [58.2%] 和 478 名 TAD [41.8%]）。共有 1060 名患者（93%）患有 N1 疾病，619 名患者（54%）患有ERBB2（以前HER2)–阳性疾病，758 例 (66%) 具有乳腺病理完全缓解。 TAD 患者更有可能接受淋巴结放射治疗（85% vs 78%；磷= .01)。 97% 的 TAD 病例和 86% 的 SLNB 病例（未定位）成功取回被夹住的淋巴结。检索到的前哨淋巴结的平均 (SD) 数量为 3 (2) vs 4 (2) (磷< .001)，切除的总淋巴结的平均 (SD) 数量为 3.95 (1.97) vs 4.44 (2.04) (磷< .001) 分别在 TAD 和 SLNB 组中。整个队列中任何腋窝、局部区域和任何侵袭性复发的 5 年发生率分别为 1.0%（95% CI，0.49%-2.0%）、2.7%（95% CI，1.6%-4.1%）和 10 %（95% CI，8.3%-13%）。 TAD 和 SLNB 的 3 年累积腋窝复发率没有差异（0.5% vs 0.8%；磷= .55）。结论和相关性该队列研究的结果表明，在这种情况下，腋窝复发很少见，并且 TAD 与 SLNB 相比，腋窝复发并没有显着降低。这些结果支持在该人群中省略 ALND。