1Department of Hepatobiliary and Pancreatic Surgery, National Cancer Center Hospital East, Kashiwa, Japan
2Department of Hepatobiliary and Pancreatic Oncology, National Cancer Center Hospital East, Kashiwa, Japan
3Department of Medical Oncology, Tochigi Cancer Center, Tochigi, Japan
4Department of Gastroenterology, Kanagawa Cancer Center, Yokohama, Japan
5Department of Hepatobiliary and Pancreatic Oncology, National Cancer Center Hospital, Tokyo, Japan
6Division of Gastrointestinal Oncology, Shizuoka Cancer Center, Shizuoka, Japan
7Department of Surgery, Kansai Medical University, Hirakata, Japan
8Department of Gastroenterological Surgery, Osaka International Cancer Institute, Osaka, Japan
9Department of Medical Oncology, Faculty of Medicine, Kyorin University, Tokyo, Japan