The aim of this study was to validate the discriminatory ability and clinical utility of the N descriptor of the newly proposed ninth edition of the TNM staging system for lung cancer in a large independent cohort. We retrospectively analyzed patients who underwent curative surgery for NSCLC between January 2004 and December 2019. The N descriptor of patients included in this study was retrospectively reclassified based on the ninth edition of the TNM classification. Survival analysis was performed using the log-rank test and Cox proportional hazard model to compare adjacent N categories. A total of 6649 patients were included in this study. The median follow-up period was 54 months. According to the newly proposed ninth edition N classification, 5573 patients (83.8%), 639 patients (9.6%), 268 patients (4.0%), and 169 patients (2.5%) were classified into the clinical N0, N1, N2a, and N2b categories and 4957 patients (74.6%), 744 patients (11.2%), 567 patients (8.5%), and 381 patients (5.7%) were classified into the pathologic N0, N1, N2a, and N2b categories, respectively. The prognostic differences between all adjacent clinical and pathologic N categories were highly significant in terms of both overall survival and recurrence-free survival. We validated the clinical utility of the newly proposed ninth edition N classification for both clinical and pathologic stages in NSCLC. The new N classification revealed clear prognostic separation between all categories (N0, N1, N2a, and N2b) in terms of both overall survival and recurrence-free survival.

中文翻译：

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国际肺癌研究协会新提出的第九版TNM分期系统N描述符的验证研究

本研究的目的是在大型独立队列中验证新提出的第九版肺癌 TNM 分期系统的 N 描述符的区分能力和临床实用性。我们回顾性分析了2004年1月至2019年12月期间接受非小细胞肺癌根治性手术的患者。本研究纳入的患者的N描述符是根据第九版TNM分类进行回顾性重新分类的。使用对数秩检验和 Cox 比例风险模型进行生存分析，以比较相邻的 N 个类别。这项研究总共纳入了 6649 名患者。中位随访期为 54 个月。根据新提出的第九版N分类，5573例患者（83.8%）、639例患者（9.6%）、268例患者（4.0%）和169例患者（2.5%）被分为临床N0、N1、N2a和N2b 类别中，病理 N0、N1、N2a 和 N2b 类别分别有 4957 名患者（74.6%）、744 名患者（11.2%）、567 名患者（8.5%）和 381 名患者（5.7%）。所有相邻临床和病理 N 类别之间的预后差异在总生存期和无复发生存期方面均非常显着。我们验证了新提出的第九版 N 分类对于 NSCLC 临床和病理阶段的临床实用性。新的 N 分类揭示了所有类别（N0、N1、N2a 和 N2b）在总生存率和无复发生存率方面的明显预后差异。