根据指南推荐，在排除了忽略pN+患者的ALND的试验中，对于ypN+阳性患者，建议进行腋窝淋巴结清扫（ALND）。我们旨在描述在ypN+疾病患者中ALND忽略的趋势。 本研究纳入了2012年至2019年在美国国家癌症数据库中接受NST（化疗或内分泌治疗）且具有ypN+疾病的成年女性乳腺浸润癌患者。如果患者在确诊后八个月内未接受明确的手术，将被排除。主要研究结果是接受ALND与忽略ALND之间的完成情况。采用双变量和多变量逻辑回归模型确定人口统计学、肿瘤特征和治疗方案的差异。 总共纳入了103,121名女性。大多数患者的cT1肿瘤（26%）或cT2肿瘤（45%），cN+疾病（71%）和导管癌组织病理学（83%）。69%的患者接受新辅助化疗，31%接受新辅助内分泌治疗而不接受化疗（30%同时接受）。77%的患者进行了ALND。自2012年以来，ALND的忽略在每年中逐渐增多，从14%增至2019年的34%。在多变量模型中，诊断年份、黑人种族、cN状态、高分级、雌激素受体+/HER2受体亚型和乳房切除术与ALND的普遍发生率显著相关。年龄、Charlson/Deyo合并疾病评分、内分泌治疗与化疗、以及辅助放射治疗与接受ALND无关。 尽管指南推荐进行ALND，但在NST后ypN+乳腺癌患者中，ALND的忽略是常见的。ALND的忽略随时间显著增加，并与临床和人口统计学因素相关。需要进一步研究确定这种方法的肿瘤学安全性。版权所有 © 2023 Elsevier Inc. 保留所有权利。

Guidelines recommend axillary lymph node dissection (ALND) for ypN + positive patients as patients receiving neoadjuvant systemic therapy (NST) were excluded from trials omitting ALND in pN + patients. We sought to characterize trends in omission of ALND in patients with ypN + disease.Adult women with invasive breast carcinoma in the National Cancer Database between 2012 and 2019 who received NST (chemotherapy or endocrine) and had ypN + disease were included. Patients were excluded if they did not have definitive surgery within eight months of diagnosis. The primary study outcome was completion of ALND versus omission. Differences in demographics, tumor characteristics, and treatment were identified using bivariate and multivariate logistic regression models.In total, 103,121 women were included. Most had cT1 (26%) or cT2 (45%) tumors, cN + disease (71%), and ductal histology (83%). 69% of patients received neoadjuvant chemotherapy and 31% neoadjuvant endocrine without chemotherapy (30% both). ALND was performed in 77% of patients. Omission of ALND became more prevalent each year from 2012 (14%) to 2019 (34%). On multivariate modeling, year of diagnosis, black race, cN status, higher grade, estrogen receptor+/HER2-receptor subtype, and mastectomy were associated with increased prevalence of ALND. Age, Charlson/Deyo comorbidity index score, endocrine versus chemotherapy, and adjuvant radiation were not associated with receipt of ALND.Despite guidelines recommending ALND, omission is common in patients with ypN + breast cancer after NST. Omission of ALND increased significantly over time and is associated with clinical and demographic factors. Future study is needed to determine the oncologic safety of this approach.Copyright © 2023 Elsevier Inc. All rights reserved.