1. Division of General Thoracic Surgery, Department of Surgery, Keio University School of Medicine, Tokyo, Japan
2. Pathology Division, Research Center for Innovative Oncology, National Cancer Center Hospital East, Kashiwa, Chiba, Japan
3. Division of Thoracic Surgery, National Cancer Center Hospital East, Kashiwa, Chiba, Japan
4. Division of Surgery, Sano Kosei General Hospital, Sano, Tochigi, Japan