1. JCOG Data Center/Operations Office, National Cancer Center Hospital, Tokyo, Japan
2. Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, Osaka, Japan
3. Division of Gastrointestinal Medical Oncology, National Cancer Center Hospital, Tokyo, Japan
4. Gastric Surgery Division, National Cancer Center Hospital, Tokyo, Japan
5. Department of Gastric Surgery, Shizuoka Cancer Center, Shizuoka, Japan