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