Surgical Choice for Clinical Stage IA Non-Small Cell Lung Cancer: View From Regional Lymph Node Metastasis

Background. We aimed to investigate the pattern of regional lymph node (LN) metastasis of early-stage nonsmall cell lung cancer (NSCLC) to provide novel rationale for surgical choice (lobectomy, segmentectomy, or wedge resection) for these patients. Methods. We retrospectively collected clinical data of patients undergoing lobectomy with systematic mediastinal LN dissection or sampling for cT1N0M0 peripheral NSCLC from January 2015 to December 2018. The regional LN metastasis pattern was analyzed based on tumor size. Results. We included a total of 354 patients for analysis. The rate of hilar or intrapulmonary LN metastasis was 13.6%. When stratified by tumor size, NSCLC less than or equal to 1 cm had no hilar or intrapulmonary LN metastasis (0%) while NSCLC greater than 2 cm but less than or equal to 3 cm had a significantly high rate of hilar or intrapulmonary LN metastasis (18.4%) and the rates of hilar, interlobar, and peripheral LN metastasis were also relatively high (5.4%, 5.4%, and 12.2%, respectively). NSCLC greater than 1.5 cm but less than or equal to 2 cm also had relatively high rates of hilar (6.5%) and peripheral (18.3%) LN metastasis, while NSCLC greater than 1 cm but less than or equal to 1.5 cm had significantly low rates of hilar or intrapulmonary (2.5%) and peripheral (2.5%) LN metastasis. Radiographic feature and histology were found to be independent predictors of regional LN metastasis. Conclusions. The pattern of regional LN metastasis in clinical stage IA peripheral NSCLC was significantly influenced by tumor size, which may provide evidence on surgical choice (lobectomy, segmentectomy, or wedge resection) for these early-stage NSCLC patients based on tumor size. (C) 2020 by The Society of Thoracic Surgeons