1. Department of Research Cancer Registry of Norway Oslo Norway
2. Unit of Virus, Lifestyle and Genes Danish Cancer Society Research Center Copenhagen Denmark
3. Department of Gynecology, Rigshospitalet University of Copenhagen Copenhagen Denmark
4. Department of Medical Epidemiology and Biostatistics Karolinska Institutet Stockholm Sweden
5. Epidemiology Merck Sharp & Dome Corporation Whitehouse Station NJ USA
6. Unit of Statistics and Pharmacoepidemiology Danish Cancer Society Research Center Copenhagen Denmark
7. Department of Laboratory Medicine Karolinska Institutet Stockholm Sweden