Risk Factors and Sampling Range Evaluation of Lymph node Metastasis for Non-small Cell Lung Cancer with Diameter ≤2 cm

Abstract

More early-stage non-small cell lung cancer (NSCLC) are diagnosed in time and treated surgically, but systematic lymph node dissection can not bring enough survival benefits for them, and even increase the probability of postoperative complications. This study aims to analyze the risk factors and evaluate mediastinal lymph node metastasis sites in different lung lobes for NSCLC with diameter ≤2 cm, so as to provide reference for surgery. We collected 1051 patients with pulmonary nodule diameter ≤2 cm who were treated by pulmonary lobectomy with lymph node sampling/dissection in Department of Thoracic Surgery of the First Affiliated Hospital with Nanjing Medical University from December 2009 to December 2019. SPSS 26.0 statistical software was used for statistical analysis, to explore the risk factors and evaluate mediastinal lymph node metastasis sites in different lung lobes. 95 of 1051 (9.04%) patients presented lymph node metastasis. Male, pathological non-adenocarcinoma, 1 cm<tumor diameter≤2 cm, spread through air spaces (STAS), visceral pleural invasion (VPI), vascular invasion, low differentiation of adenocarcinoma, and micropapillary or solid adenocarcinoma subtype were the risk factors for lymph node metastasis (P<0.01). Male, 1 cm<tumor diameter≤2 cm, STAS, VPI and vascular invasion were independent risk factors for lymph node metastasis (P<0.05). Lymph node metastasis of #2R, #4R, #9 appeared in upper and middle lobe of right lung (P<0.05), and #7 appeared in right lower lobe (P<0.05). Lymph node metastasis of #5 and #6 in the left upper lobe was more common (P<0.05), while metastasis of #7 and #9 had no significant difference (P>0.05). Lymph nodes in group N1 were significantly correlated with lymph node metastasis in groups #2R, #4R, #5, #6, #7 and #9 (P<0.01). Lobe-specific lymph node dissection (LSND) can be performed for early-stage NSCLC. Male, pathological non-adenocarcinoma, 1 cm<tumor diameter≤2 cm, STAS, VPI, vascular invasion, low differentiation of adenocarcinoma, and micropapillary or solid adenocarcinoma subtype would increase the risk of lymph node metastasis.