1. Department of Surgery Surgical Oncology and Science Sapporo Medical University School of Medicine Sapporo Japan
2. Hokkaido Pancreatic Cancer Study Group; HOPS Sapporo Japan
3. Department of Gastroenterological Surgery II Hokkaido University Faculty of Medicine Sapporo Japan
4. Center for Gastroenterology Teine‐Keijinkai Hospital Sapporo Japan
5. Department of Gastroenterology and Hepatology Hokkaido University Graduate School of Medicine Sapporo Japan
6. Department of Gastroenterology and Hepatology Sapporo Medical University School of Medicine Sapporo Japan
7. Department of Medical Oncology Sapporo Medical University School of Medicine Sapporo Japan
8. Division of Metabolism and Biosystemic Science Department of Medicine Asahikawa Medical University Sapporo Japan
9. Division of Gastroenterology and Hematology/Oncology Department of Medicine Asahikawa Medical University Sapporo Japan
10. Department of Radiology Tonan Hospital Sapporo Japan