1. Department of Surgery, Keio University School of Medicine, Tokyo, Japan
2. Second Department of Surgery, Hamamatsu Medical University School of Medicine, Shizuoka, Japan
3. Department of Gastrointestinal Surgery, The Jikei University Kashiwa Hospital, Tokyo, Japan
4. Department of Surgery, The Jikei University Hospital, Tokyo, Japan
5. Division of Gastric Surgery, Shizuoka Cancer Center, Shizuoka, Japan
6. Department of Surgery, National Defense Medical College Hospital, Saitama, Japan
7. Department of Surgical Oncology, Kanazawa Medical University, Ishikawa, Japan
8. Department of Digestive Surgery, Breast and Thyroid Surgery, Field of Oncology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
9. Department of Gastroenterological Surgery, Mie University Hospital, Mie, Japan
10. Department of Gastroenterological Surgery, Ishikawa Prefectural Central Hospital, Ishikawa, Japan
11. Department of Gastroenterological Surgery, Kanazawa University Hospital, Ishikawa, Japan
12. Department of Esophageal-Gastro-Intestinal Surgery, Chiba University Hospital, Chiba, Japan
13. Department of Gastroenterological Surgery, Tokai University Hospital, Kanagawa, Japan
14. Department of Surgery, Tokai Central Hospital, Gifu, Japan
15. Department of Preventive Medicine and Public Health, Keio University School of Medicine, Tokyo, Japan