1. Department of Surgery Southern Tohoku General Hospital Koriyama Japan
2. Department of Minimally Invasive Surgical and Medical Oncology Fukushima Medical University Fukushima Japan
3. Department of Gastroenterological Surgery Cancer Institute Hospital, Japanese Foundation for Cancer Research Tokyo Japan
4. Department of Gastric Surgery National Cancer Center Hospital East Kashiwa Japan
5. Department of Surgery Keio University School of Medicine Tokyo Japan
6. Department of Digestive Surgery Niigata Cancer Center Hospital Niigata Japan