1. Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Korea.
2. Division of Medical Oncology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
3. Division of Pulmonology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
4. Department of Thoracic and Cardiovascular Surgery, Yonsei University College of Medicine, Seoul, Korea.