1. Department of Oncology, Haukeland University Hospital, Bergen, Norway;
2. Gades Institute, Department of Pathology, Haukeland University Hospital, Bergen, Norway;
3. Department of Radiology, Haukeland University Hospital, Bergen, Norway;
4. Cancer Registry of Norway, Institute of Population Based Cancer Research, Oslo, Norway;
5. Department of Gastrointestinal Surgery, Haukeland University Hospital, Bergen, Norway;
6. Department of Surgery, Haugesund Hospital, Haugesund, Norway;
7. Department of Gastrointestinal Surgery, Stavanger University Hospital, Stavanger, Norway;
8. Institute of Clinical Medicine, Faculty of Medicine and Odontology, University of Bergen, Norway;
9. Institute of Clinical Science, Faculty of Medicine and Odontology, University of Bergen, Bergen, Norway