Is Video-assisted Thoracoscopic Lobectomy a Clinical Alternative for Surgically Resectable Pathologic N2 NSCLC Patients

Inclusion Criteria: * Patients with age \> 18 years old; * Patients with pathologically diagnosed non-small cell lung cancer; * Patients underwent lobectomy by either VATS or thoracotomy between 2014 and 2017; * Patients who received lymphadenectomy for all accessible lymph nodes; * Patients with N2 lymph nodes (+) after surgeries; Exclusion Criteria: * Patients with second primary tumors or multiple primary tumors; * Patients who received chest surgeries before hospitalization; * Patients with superior pulmonary sulcus tumor