1. Gastric Surgery Division National Cancer Center Hospital East Kashiwa Japan
2. Department of Minimally Invasive Surgical and Medical Oncology Fukushima Medical University Fukushima Japan
3. Department of Digestive Surgery Niigata Cancer Center Hospital Niigata Japan
4. Department of Surgery National Center for Global Health and Medicine Tokyo Japan
5. Departoment of Gastroenterological Surgery Cancer Institute Hospital Japanese Foundation for Cancer Research Tokyo Japan
6. Department of Biostatistics School of Data Science Yokohama City University Yokohama Japan
7. Department of Surgery Kitasato University Sagamihara Japan