1. Unit of Virus, Lifestyle and Genes, Danish Cancer Society Research Center, Copenhagen, Denmark;
2. Memorial Sloan Kettering Cancer Center, New York, NY, USA;
3. Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark;
4. Unit of Statistics and Pharmacoepidemiology, Danish Cancer Society Research Center, Copenhagen, Denmark;
5. Department of Public Health, University of Copenhagen, Copenhagen, Denmark