1. Department for Upper Abdominal Diseases, Karolinska University Hospital, 141 86 Stockholm, Sweden
2. Department of Medicine Huddinge, Karolinska Institute, 141 86 Stockholm, Sweden
3. Department of Transplantation Surgery, Karolinska Institute, 141 86 Stockholm, Sweden
4. Faculty of Medicine, Uppsala University, 753 10 Uppsala, Sweden
5. Division of Epidemiology and Biostatistics, IEO, European Institute of Oncology IRCCS, 20141 Milan, Italy
6. Department of Clinical Science, Intervention, and Technology (CLINTEC), Karolinska Institute, 171 77 Stockholm, Sweden