1. Second Department of Surgery, Dokkyo Medical University, Mibu, Japan
2. Hepato-Pancreatico-Biliary Surgery Division, Department of Surgery, Graduate School of Medicine, Tokyo, Japan
3. Department of Hepato-Biliary-Pancreatic Surgery, Osaka City University Graduate School of Medicine, Osaka, Japan
4. Department of Gastroenterology, Musashino Red Cross Hospital, Tokyo, Japan
5. National Centre for Global Health and Medicine, Keio University School of Medicine, Tokyo, Japan
6. Department of Pathology, Keio University School of Medicine, Tokyo, Japan
7. Department of Gastroenterology, Juntendo University School of Medicine, Tokyo, Japan
8. Department of Digestive Surgery, Nihon University School of Medicine, Tokyo, Japan
9. Department of Clinical Laboratory Medicine, Kurume University Hospital, Kurume, Japan
10. Department of Biostatistics, School of Public Health, University of Tokyo, Tokyo, Japan
11. Department of Radiology, Kobe University School of Medicine, Kobe, Japan
12. Department of Gastroenterology and Hepatology, Kinki University School of Medicine, Osaka, Japan