1. Department of Gastroenterological and Transplant Surgery, Hiroshima Prefectural Hospital
2. Division of Clinical Oncology, Hiroshima Prefectural Hospital
3. Department of Gastroenterological and Transplant Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University
4. Department of Surgery, Chugoku Rosai Hospital
5. Department of Surgery, National Hospital Organization Higashihiroshima Medical Centre
6. Department of surgery, JR Hiroshima Hospital
7. Department of Surgery, National Hospital Organization Kure Medical Centre
8. Department of Surgery, Kure City Medical Association Hospital
9. Department of Surgery, Onomichi General Hospital
10. Department of Surgery, Hiroshima city Asa Hospital
11. Department of Epidemiology, Infectious Disease Control and Prevention, Institute of Biomedical and Health Sciences, Hiroshima University