1. Department of Medical Oncology and Hematology, Oita University Faculty of Medicine, Yufu, Japan
2. Japan Clinical Oncology Group Data Center/Operations Office, National Cancer Center Hospital, Tokyo, Japan
3. Department of Gastroenterology, Kanagawa Cancer Center, Yokohama, Japan
4. Division of Gastrointestinal Medical Oncology, National Cancer Centre Hospital, Tokyo, Japan
5. Comprehensive Cancer Center, National Center for Global Health and Medicine, Tokyo, Japan
6. Department of Medical Oncology, Hamamatsu University School of Medicine, Hamamatsu, Japan
7. Department of Surgery, Yodogawa Christian Hospital, Osaka, Japan
8. Department of Gastric Surgery, National Cancer Center Hospital, Tokyo, Japan
9. Division of Gastric Surgery, Shizuoka Cancer Center, Shizuoka, Japan