Risk Factors of Medistinal Metastasis in Endoscopic Staging of Lung Cancer

The purpose of this study is to investigate risk factors for mediastinal lymph node metastasis in potentially operable non-small cell lung cancer in order to find indications for endoscopic mediastinal staging. Chest CT, integrated PET/CT, and endobronchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA) +/- endoscopic ultrasound with bronchoscope-guided fine needle aspiration (EUS-B-FNA) are performed for mediastinal staging. CT and PET/CT findings, histologic types and other risk factors will be analyzed. The investigators develop the prediction method for mediastinal metastasis.