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