1. Upper Gastrointestinal Surgery, Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden;2. Centre for Clinical Research Sörmland, Uppsala University, Eskilstuna, Sweden;3. Department of Surgery and Cancer, Imperial College London, London, United Kingdom;4. Department of Public Health and Nursing, NTNU, Norwegian University of Science and Technology, Trondheim/Levanger, Norway;5. Medical Department, Levanger Hospital, Nord-Trøndelag Hospital Trust, Levanger, Norway;6. Surgery Research Unit, Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland;7. Abdominal Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland;8. Nykøbing Falster Hospital, University of Copenhagen, Copenhagen, Denmark;9. Finnish Cancer Registry, Institute for Statistical and Epidemiological Cancer Research, Helsinki, Finland;10. Faculty of Social Sciences, Tampere University, Tampere, Finland;11. Icelandic Cancer Registry, Icelandic Cancer Society, Reykjavik, Iceland;12. Faculty of Medicine, University of Iceland, Reykjavik, Iceland;13. Department of Public Health, University of Copenhagen, Copenhagen, Denmark;14. School of Cancer and Pharmaceutical Sciences, King’s College London, London, United Kingdom
