1. Division of Gastroenterological SurgerySaitama Cancer Center Kitaadachi‐gun Saitama Japan
2. Faculty of Medicine, Gastroenterological and Pediatric SurgeryOita University Yufu Oita Japan
3. JCOG Operations OfficeNational Cancer Center Hospital Tokyo Japan
4. JCOG Data CenterNational Cancer Center Hospital Tokyo Japan
5. Department of SurgeryHiratsuka City Hospital Hiratsuka Kanagawa Japan
6. Department of Colorectal SurgeryNational Cancer Center Hospital East Kashiwa Chiba Japan
7. Department of SurgeryKyorin University Tokyo Japan
8. Department of SurgeryKitasato University School of Medicine Sagamihara Kanagawa Japan
9. Department of Medical OncologyKochi Health Sciences Center Kochi Japan
10. Oita University Oita Japan