1. Department of Gastrointestinal Surgery ,Oslo University Hospital, PO Box 4950 Nydalen N-0424 Oslo Norway
2. Department of Registration, Cancer Registry of Norway, Oslo, Norway Department of Research and Innovation, Møre and Romsdal Hospital Trust, Ålesund, Norway
3. Department of Research, Cancer Registry of Norway, Oslo, Norway
4. Department of Registration, Cancer Registry of Norway, Oslo, Norway
5. Department of Gastrointestinal Surgery, Oslo University Hospital, Oslo, Norway Institute of Clinical Medicine, University of Oslo, Norway
6. Division for Molecular Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
7. Department of Gastrointestinal Surgery, Oslo University Hospital, Oslo, NorwayInstitute of Clinical Medicine, University of Oslo, Norway