1. Department of Gastrointestinal and Paediatric Surgery, Oslo University Hospital, Oslo, Norway
2. Department of Registration, The Cancer Registry of Norway, Oslo, Norway
3. Department of Research and Innovation, Møre and Romsdal Hospital Trust, Ålesund, Norway
4. Department of Research, The Cancer Registry of Norway, Oslo, Norway
5. Division for Molecular Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
6. Institute of Clinical Medicine, University of Oslo, Oslo, Norway