Distinct Lymph Node Metastasis Patterns Between Lung Adenocarcinoma and Lung Squamous Cell Carcinoma

Abstract Purpose: The lymph node metastasis pattern of non-small-cell lung cancer remains controversial. Here, we hypothesize that there are distinct lymph node metastasis patterns between lung adenocarcinoma and lung squamous cell carcinoma.Methods: Patients diagnosed with lung adenocarcinoma and lung squamous cell carcinoma from 2004 to 2013 were identified in the SEER database. Multivariate binary logistic regression analyses were performed to estimate the risk of pathology type on N1/N2 lymph node metastases. Variables with significant p values (p < 0.05) in the regression analysis were selected to construct a nomogram. Data from West China hospital cohort was used for validation.Results: A total of 14,673 patients were enrolled in this study, including 10,143 patients with lung adenocarcinomas and 4,530 patients with lung squamous cell carcinomas. In the lung adenocarcinoma cases, there were 7,798 (76.9%) N0 cases, 1,222 (12.0%) N1 cases and 1,123 (11.1%) N2 cases. In the lung squamous cell carcinoma cases, there were 3,359 (74.2%) N0 cases, 753 (16.6%) N1 cases and 418 (9.2%) N2 cases (p < 0.001). Lung squamous cell carcinoma patients were more likely to have N1 lymph node metastasis (OR: 1.143, 95%CI: 1.028-1.270, p = 0.014), while lung adenocarcinoma patients were more likely to have N2 lymph node metastasis (OR: 1.460, 95%CI: 1.289-1.653, p < 0.001)Conclusions: This population-based study revealed that lung adenocarcinoma and lung squamous cell carcinoma have distinct lymph node metastasis patterns. Nomograms for visually predicting the risk of lymph node metastasis would have the potentials to guide physicians in clinical decision making.