1. JCOG Data Center/Operations Office, National Cancer Center Hospital , Tokyo , Japan
2. Department of Surgery, Keio University School of Medicine , Tokyo , Japan
3. Department of Clinical Oncology, Kyoto University Hospital , Kyoto , Japan
4. Department of Head and Neck , Esophageal Medical Oncology, , Tokyo , Japan
5. National Cancer Center Hospital , Esophageal Medical Oncology, , Tokyo , Japan
6. Graduate School of Business Administration, Keio University , Yokohama , Japan
7. Graduate School of Health Management, Keio University , Fujisawa, Kanagawa , Japan
8. Department of Preventive Medicine and Public Health , School of Medicine, , Tokyo , Japan
9. Keio University , School of Medicine, , Tokyo , Japan
10. Division of Gastrointestinal Oncology, Shizuoka Cancer Center , Shizuoka , Japan
11. Department of Surgery, Hamamatsu University School of Medicine , Hamamatsu , Japan