1. Department of Community MedicineFaculty of Health Sciences, UiT, The Arctic University of NorwayTromsø Norway
2. Department of Medical Epidemiology and BiostatisticsKarolinska InstitutetStockholm Sweden
3. Department of ResearchCancer Registry of Norway, Institute of Population‐Based Cancer ResearchOslo Norway
4. Genetic Epidemiology Group, Folkhälsan Research Centre, Samfundet FolkhälsanHelsinki Finland