1. Department of Surgery, Teikyo University School of Medicine, Tokyo 170-8582, Japan
2. Department of Thoracic Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
3. Department of Thoracic Surgical Oncology, Cancer Institute Hospital, Tokyo 135-8550, Japan
4. Department of General Thoracic Surgery, Osaka University Graduate School of Medicine, Suita 565-0871, Japan
5. Department of Thoracic Surgery, Aichi Cancer Center Hospital, Nagoya 464-8681, Japan
6. Department of Thoracic Surgery, Chiba Cancer Center, Chiba 260-8670, Japan
7. Department of Thoracic Surgery, Yamagata Prefectural Central Hospital, Yamagata 990-2292, Japan
8. Division of Chest Surgery, Department of Surgery, School of Medicine, Toho University, Tokyo 143-8541, Japan
9. Department of General Thoracic Surgery, Dokkyo Medical University, Mibu 321-0293, Japan
10. Department of General Thoracic Surgery, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan
11. Department of Thoracic Surgery, Tokyo Medical University, Tokyo 160-0023, Japan
12. Division of Thoracic Surgery, Tochigi Cancer Center, Utsunomiya 320-0834, Japan
13. First Department of Surgery, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan
14. Department of Thoracic Surgery, National Defense Medical College, Saitama 359-8513, Japan