1. Department of Oncology, Akershus University Hospital, Lørenskog, Norway
2. Institute of Clinical Medicine, University of Oslo, Oslo, Norway
3. Department of Tumor Biology, Oslo University Hospital, Oslo, Norway
4. Institute for Medical Biology, University of Tromsø – The Arctic University of Norway, Tromsø, Norway
5. Department of Gastroenterological Surgery, Oslo University Hospital, Oslo, Norway
6. Department of Pathology, Oslo University Hospital, Oslo, Norway
7. Department of Cancer Genetics, Oslo University Hospital, Oslo, Norway
8. Institute of Health and Society, University of Oslo, Oslo, Norway
9. Health Service Research Unit, Akershus University Hospital, Lørenskog, Norway
10. Division for Health Services, Norwegian Institute of Public Health, Oslo, Norway