1. Upper Gastrointestinal Surgery, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, and Karolinska University Hospital, Sweden
2. Department of Public Health, University of Copenhagen, Denmark
3. Nuffield Department of Surgery, University of Oxford, United Kingdom
4. Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Solna, Sweden
5. Department of Public Health and Nursing, NTNU, Norwegian University of Science and Technology, Trondheim/Levanger, Norway
6. Medical Department, Levanger Hospital, Nord-Trøndelag Hospital Trust, Levanger, Norway
7. Department of Surgery, Oulu University Hospital and University of Oulu, Oulu, Finland
8. School of Cancer and Pharmaceutical Sciences, King’s College London, United Kingdom