1. Department of Laboratory Medicine; Clinical Microbiology, Lund University, Skåne University Hospital; Malmö; Sweden
2. Finnish Cancer Registry; Institute for Statistical and Epidemiological Cancer Research; Helsinki; Finland
3. Cancer Registry of Norway; Institute of Population-Based Cancer Research; Oslo; Norway
4. Division of Genome Modifications and Carcinogenesis; Infection and Cancer Program, German Cancer Research Center (DKFZ); Heidelberg; Germany