Hyogo Medical University, Wakayama Medical University, Wakayama Medical University, Kansai Medical University, Nara Medical University School of Medicine - Department of Surgery, Nagoya University, Kindai University, University of Toyama, Shimane University, Hiroshima University Graduate School of Biomedical and Health Sciences - Department of Surgery, Osaka Metropolitan University, Kagoshima University, Tokyo Medical University, Kumamoto University, Kyoto Prefectural University, Kyushu University, Wakayama Medical University, Wakayama Medical University, Wakayama Medical University and Showa University

The University of Osaka, Hamamatsu University, The University of Osaka - Department of Gastroenterological Surgery, Japanese Foundation for Cancer Research - Cancer Institute Hospital, Shizuoka Cancer Center, Kindai University, Gifu University, National Cancer Center Hospital, Saitama University - Saitama Medical University, National Cancer Center Hospital - Department of Gastric Surgery, Yokohama City University, University of Tokyo, Kansai Rosai Hospital, Wakayama Medical University, Japanese Foundation for Cancer Research - Cancer Institute Hospital and Keio University - Department of Surgery