1. Division of Gastric Surgery Shizuoka Cancer Center Nagaizumi‐Cho Japan
2. Japan Clinical Oncology Group Data Center/Operations Office, National Cancer Centre Hospital Tokyo Japan
3. Department of Gastroenterological Surgery Osaka University Graduate School of Medicine Osaka Japan
4. Department of Gastroenterological Surgery, Graduate School of Medical Sciences Nagoya City University Nagoya Japan
5. Department of Surgery Hiroshima City Asa Citizens Hospital Hiroshima Japan
6. Department of Surgery Toyonaka Municipal Hospital Toyonaka Japan
7. Department of Surgery Hakodate Goryoukaku Hospital Hakodate Japan
8. Department of Gastroenterological Surgery Aichi Cancer Center Hospital Nagoya Japan
9. Gastric Surgery Division National Cancer Center Hospital Tokyo Japan
10. Department of Gastroenterological Surgery Cancer Institute Ariake Hospital Tokyo Japan
11. Department of Gastroenterological Surgery Hyogo College of Medicine Nishinomiya Japan
12. Department of Surgery Yodogawa Christian Hospital Osaka Japan