1. Department of Head and Neck Esophageal Medical Oncology, National Cancer Center Hospital, Tokyo, Japan;
2. Department of Radiation Oncology, Showa University School of Medicine, Tokyo, Japan;
3. Department of Esophageal Surgery, National Cancer Center Hospital, Tokyo, Japan;
4. Department of Gastrointestinal Surgery, Tokai University School of Medicine, Isehara, Japan;
5. Division of Gastrointestinal Surgery, Kanagawa Cancer Center, Yokohama, Japan;
6. Saitama Cancer Center, Saitama, Japan;
7. Department of Gastrointestinal Medical Oncology, National Cancer Center Hospital East, Chiba, Japan;
8. Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, Nagoya, Japan;
9. Niigata Cancer Center Hospital, Niigata, Japan;
10. Department of Surgery, Shizuoka General Hospital, Shizuoka, Japan;
11. Department of Surgery, Keio University School of Medicine, Tokyo, Japan;
12. Department of Gastroenterological Surgery, Kochi Health Sciences Center, Kochi, Japan;
13. Division of Esophageal Surgery, Shizuoka Cancer Center, Shizuoka, Japan;
14. Department of Gastroenterological Oncology, Hyogo Cancer Center, Akashi, Japan;
15. Department of Gastrointestinal Medical Oncology, National Hospital Organization Shikoku Cancer Center, Matsuyama, Japan;
16. Department of Gastroenterological Surgery, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan;
17. Gastroenterological Surgery, Toranomon Hospital, Tokyo, Japan;
18. Japan Clinical Oncology Group Data Center/Operations Office, National Cancer Center Hospital, Tokyo, Japan;
19. National Cancer Center Hospital, Tokyo, Japan;