CHEST Original Research LUNG CANCER

Lung cancer is the leading cause of cancer-related death worldwide. 1 Surgical resection is the stan-dard curative treatment modality for early-stage non-small cell lung cancer (NSCLC). 2 Accurate staging of lymph node (LN) involvement is a critical aspect of initial management of patients with NSCLC. It often infl uences decisions about the propriety and timing of treatment. N1 disease is a heterogeneous group of NSCLC conditions with varying survival rates. 3 During the past 20 years, many studies have evaluated the validity of the N descriptors and have suggested refi nements Background: The non-small cell lung cancer (NSCLC) staging system (published in 2009 in the seventh edition of the cancer staging manuals of the Union for International Cancer Control and American Joint Commission on Cancer) did not include any changes to current N descriptors for NSCLC. However, the prognostic signifi cance of the extent of lymph node (LN) involvemen