在一个前瞻性、多中心国家数据库中，确定非小细胞肺癌患者中隐匿N1/N2淋巴结转移的发生率及相关风险因素，这些患者肿瘤不超过3厘米，并且经CT和PET-CT判定为cN0。从2016年至2018年在全国多个中心进行解剖性肺切除手术的3533名患者中，选取PET-CT和CT扫描判定为cN0的非小细胞肺癌患者，且这些患者至少接受过肺叶切除手术。比较pN0患者和pN1/N2患者的临床和病理变量，以确定与淋巴结转移存在相关的因素。分类变量使用卡方检验，数值变量使用Mann-Whitney U检验。单因素分析中p<0.2的所有变量都包含在多元逻辑回归分析中。该研究共包括1205名患者。隐匿性pN1/N2病变的发生率为10.70%（95%CI，9.01-12.58）。多元分析显示：肿瘤分化程度、大小、位置（中心或周边）、PET中的SUV、手术经验和切除的淋巴结数量与隐匿性N1/N2淋巴结转移有关。对于肺癌cN0型3厘米及以下的瘤体，隐匿性N1/N2病变的发生率不容忽视。了解肿瘤分化程度、CT扫描中的瘤体大小、PET-CT中瘤体的最大吸收、位置（中心或周边）、切除的淋巴结数和手术医生的经验等数据是重要的，以便检测危险患者。版权所有©2023 SEPAR。由Elsevier España，S.L.U.出版，版权所有。

To determine the incidence of occult N1/N2 nodal metastases and associated risk factors in patients with non-small cell lung cancer no larger than 3cm and deemed cN0 by CT and PET-CT in a prospective, multicentre national database.Patients with a NSCLC no larger than 3cm, deemed cN0 by PET-CT and CT scan, who had undergone at least a lobectomy, were selected from a national multicentre database of 3533 patients who had undergone anatomic lung resection between 2016 and 2018. Clinical and pathological variables of patients with pN0 and patients with pN1/N2 were compared to identify factors associated with the presence of lymph node metastases. Chi2 and the Mann-Whitney U test were used for categorical and numerical variables, respectively. All variables with p<0.2 in the univariate analysis were included in the multivariate logistic regression analysis.The study included 1205 patients from the cohort. The incidence of occult pN1/N2 disease was 10.70% (95%CI, 9.01-12.58). The multivariable analysis revealed that the degree of differentiation, size, location (central or peripheral) and SUV of the tumour in PET, surgeon experience and number of lymph nodes resected were associated with occult N1/N2 metastases.The incidence of occult N1/N2 in patients with bronchogenic carcinoma with cN0 tumours no larger than 3cm is no negligible. Data about the degree of differentiation, tumour size in CT scan, maximal uptake of the tumour in PET-CT, location (central or peripheral), number of lymph nodes resected and surgeon seniority is relevant in order to detect patients at risk.Copyright © 2023 SEPAR. Published by Elsevier España, S.L.U. All rights reserved.