1. Department of Oncology, Ostfold Hospital Trust, Kalnes, Norway;
2. Department of Oncology, Oslo University Hospital, Oslo, Norway;
3. Department of Medicine, Ostfold Hospital Trust, Kalnes, Norway;
4. Department of Biostatistics, Oslo University Hospital, Oslo, Norway;
5. Center for Cancer Biomedicine, University of Oslo, Oslo, Norway;
6. Department of Pathology, Oslo University Hospital, Oslo, Norway