National Cancer Center Hospital - Gastrointestinal Medical Oncology Division, National Cancer Center Hospital, Showa University, National Cancer Center Hospital, Tokai University, Kanagawa Cancer Center - Department of Gastrointestinal Surgery, Saitama Cancer Center, Aichi Cancer Center, Aichi Cancer Center, Niigata Cancer Center Hospital, Shizuoka General Hospital, Keio University, Kochi University - Kochi Health Sciences Center, Shizuoka Cancer Center, Hyogo Cancer Center, Shikoku Cancer Centre, Kumamoto University - Department of Gastroenterological Surgery, Toranomon Hospital, Hamamatsu University, National Cancer Center Hospital, Keio University - Department of Surgery and Independent

Hamamatsu University, National Cancer Center Hospital, Nagoya University - Nagoya University Hospital, Shizuoka Cancer Center, Hamamatsu University, Keio University, Okayama University, Toranomon Hospital, Shizuoka Cancer Center, Niigata Cancer Center Hospital, Niigata Cancer Center Hospital, Hiroshima University - Hiroshima University Hospital, Shikoku Cancer Centre, National Cancer Center Hospital, Tokai University, Keio University, National Cancer Center Hospital - Gastrointestinal Medical Oncology Division, Japan Clinical Oncology Group Data Center/Operations Office, Kobe City Medical Center General Hospital, Keio University - Department of Surgery and Independent