1. Faculty of Medicine, University of Oslo, Oslo, Norway;
2. Department of Oncology–Pathology, Karolinska University Hospital and Karolinska Institutet, Stockholm, Sweden;
3. Institute of Clinical Medicine - Oncology, University of Tromsø and University Hospital of North Norway, Tromsø, Norway;
4. The Cancer Clinic, St. Olavs Hospital, Trondheim, Norway;
5. Department of Oncology, University Hospital of Oslo, Oslo, Norway