Osaka Medical College - Department of Medical Statistics, Osaka International Cancer Institute, Niigata University, Niigata University, Osaka International Cancer Institute, National Cancer Center Hospital - Department of Gastric Surgery, Cancer Institute Ariake Hospital, National Cancer Center Hospital - Endoscopy Division, National Tokyo Medical Center, Tottori University, Shizuoka Cancer Centre, Kitasato University - Research and Development Center for New Frontiers, Teikyo University, Kobe University, Kobe University - Division of Gastrointestinal Surgery, Hyogo College of Medicine, The John Wayne Cancer Institute, The John Wayne Cancer Institute and Independent