1. Department of Surgery, Keio University School of Medicine
2. Biostatistics Division, Clinical Research Support Center, The University of Tokyo Hospital
3. Department of Minimally Invasive Surgical and Medical Oncology, Fukushima Medical University
4. Department of Biostatistics, Graduate School of Medicine, The University of Tokyo
5. Department of Surgery, Yokohama City University
6. Department of Gastroenterological Surgery (Surgery II), Nagoya University Graduate School of Medicine
7. Cancer Treatment Center, Kochi Medical School Hospital
8. Faculty of Engineering, Tokyo University of Science
9. Department of Surgery, Tokai University
10. Tokai Central Hospital
11. Japanese Foundation for Multidisciplinary Treatment of Cancer
12. Department of Gastric Surgery, National Cancer Center Hospital