1. Department of Cancer Genetics, Institute for Cancer Research, Oslo University Hospital , Oslo , Norway
2. Institute of Clinical Medicine, Faculty of Medicine, University of Oslo , Oslo, Norway
3. Department of Medical Genetics, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo , Oslo, Norway
4. Cancer Registry of Norway , Oslo, Norway
5. Oslo Centre for Biostatistics and Epidemiology, Department of Biostatistics, Faculty of Medicine, University of Oslo , Oslo, Norway