1. Department of Digestive Surgery, Nihon University School of Medicine, Tokyo, Japan
2. Department of Biostatistics, School of Public Health, University of Tokyo, Tokyo, Japan
3. Department of Gastroenterology, Juntendo University School of Medicine, Tokyo, Japan
4. Department of Gastroenterology, Musashino Red Cross Hospital, Tokyo, Japan
5. Department of Hepato-biliary-pancreatic Surgery, School of Medicine, University of Tokyo, Tokyo, Japan
6. Department of Hepato-biliary-pancreatic Surgery, National Center for Global Health and Medicine, Tokyo, Japan
7. Department of Pathology, Keio University School of Medicine, Tokyo, Japan
8. Department of Hepato-biliary-pancreatic Surgery, Osaka City University Graduate School of Medicine, Osaka, Japan
9. Department of Gastroenterology and Hepatology, Kinki University School of Medicine, Osaka-Sayama, Japan
10. Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan
11. Department of Clinical Laboratory Medicine, Kurume University Hospital, Kurume, Japan