Department of Hepatobiliary and Pancreatic Oncology, National Cancer Center Hospital East, Kashiwa masikeda@east.ncc.go.jp. Department of Hepatobiliary and Pancreatic Oncology, National Cancer Center Hospital East, Kashiwa. Department of Biostatistics, Kyoto University School of Public Health, Kyoto. Department of Hepatobiliary and Pancreatic Medical Oncology, Kanagawa Cancer Center, Yokohama. Department of Gastroenterology, National Center for Global Health and Medicine Center Hospital, Tokyo. Department of Diagnostic and Interventional Radiology, Aichi Cancer Center Hospital, Nagoya. Department of Hepatology, Osaka City University Hospital, Osaka. Department of Gastroenterology and Hepatology, Kinki University School of Medicine, Osaka. Department of Hepatobiliary and Pancreatic Surgery, Osaka National Hospital, Osaka. Department of Gastroenterology, Kanazawa University Hospital, Kanazawa. Department of Hepato-Biliary-Pancreatology, National Hospital Organization Kyushu Cancer Center, Fukuoka. Department of Gastroenterology, Saiseikai Utsunomiya Hospital, Tochigi. Department of Gastroenterology, Sapporo Kosei General Hospital, Sapporo. Department of Molecular Gastroenterology and Hepatology, Kyoto Prefectural University of Medicine, Kyoto. Institute for Advancement of Clinical and Translational Science, Kyoto University Hospital, Kyoto. Clinical Research Center, Shikoku Cancer Center, Matsuyama. Department of Medical Oncology, Kyorin University, Tokyo. Department of Hepatobiliary and Pancreatic Oncology, National Cancer Center Hospital, Tokyo, Japan.