1. JCOG Data Center/Operations Office, National Cancer Center, Japan.
2. Gastric Surgery Division, National Cancer Center Hospital, Tokyo, Japan.
3. Department of Gastrointestinal Surgery, Kanagawa Cancer Center, Yokohama, Japan.
4. Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, Nagoya, Japan.
5. Gastric Surgery Division, National Cancer Center Hospital East, Chiba, Japan.
6. Department of Surgery, Hyogo College of Medicine, Hyogo, Japan.