1. Hepatobiliary and Pancreatic Oncology Kanagawa Cancer Center Yokohama Kanagawa Japan
2. Department of Gastroenterology Yokohama City University Graduate School of Medicine Yokohama Kanagawa Japan
3. Department of Gastroenterology, Internal Medicine Kitasato University School of Medicine Sagamihara Kanagawa Japan
4. Gastroenterological Center Yokohama City University Medical Center Yokohama Kanagawa Japan
5. Division of Gastroenterology and Hepatology, Department of Internal Medicine Tokai University School of Medicine Isehara Kanagawa Japan
6. Division of Gastroenterology and Hepatology, Department of Internal Medicine St. Marianna University School of Medicine Kawasaki Kanagawa Japan
7. Division of Gastroenterology and Hepatology Kawasaki Municipal Tama Hospital Kawasaki Kanagawa Japan
8. Department of Biostatistics, School of Medicine Yokohama City University Yokohama Kanagawa Japan
9. Gastroenterology Division Hadano Red Cross Hospital Hadano Kanagawa Japan