Supplemental Table. A list of institutions that contributed to this study

Department of Surgical Oncology, Hokkaido University Graduate School of Medicine Department of Hepatobiliary Pancreatic Surgery, National Cancer Center Hospital East Second Department of Surgery, Wakayama Medical University, School of Medicine Department of Surgery, Nagoya University School of Medicine Department of Surgery, Kansai Medical University Department of Surgery, Nara Medical University Graduate School of Medicine Department of Surgery, Graduate School of Medicine, Osaka University Department of Gastroenterological Surgery, Akita University Division of Gastroenterological Surgery, Hyogo Cancer Center Department of Surgical Oncology, Kagoshima University Division of Hepato-Biliary-Pancreatic Surgery and Transplantation, Department of Surgery, Kyoto University Hepatobiliary and Pancreatic Surgery Division, National Cancer Center Hospital Division of Gastroenterological and General Surgery, Asahikawa Medical University Division of Gastroenterological Surgery, Chiba Cancer Center Hospital Department of General Surgery, Graduate School of Medicine, Chiba University Department of Gastroenterological Surgery, Fujita Health University Department of Surgery, Hamamatsu University School of Medicine Department of Surgery, Hirosaki University School of Medicine Department of Surgery, Graduate School of Biochemical Sciences, Hiroshima University Department of Surgery, Hokkaido Gastroenterology Hospital Department of Surgery, Jichi Medical University Department of Surgery, Jikei Kashiwa Hospital Division of Gastroenterological Surgery, Kochi Health Sciences Center Department of Surgery, Kurume University, School of Medicine Department of Surgery, Oita Red Cross Hospital Department of Surgery, Okayama Saiseikai Genaral Hospital Department of Gastroenterological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Department of Surgery, Osaka National Hospital Department of Surgery, Osaka Medical Center for Cancer and Cardiovascular Disease Department of Gastroenterological Surgery, St. Marianna University School of Medicine Department of Surgery, Teikyo University School of Medicine Department of Surgery, Teine-Keijinkai Hospital Department of Surgery, Toho University Ohashi Medical Center Division of Gastroenterological Surgery, Graduate School of Medicine, Tohoku University Third Department of Surgery, Tokyo Medical University Department of Hepato-Biliary-Pancreatic Surgery, Tokyo Metropolitan Komagome Hospital Department of Surgery, Tottori Municipal Hospital Department of Surgery, Graduate School of Medicine, Tottori University Department of Surgery, Toyama Prefectural Central Hospital