1. Department of Pathology; VU University Medical Center; Amsterdam The Netherlands
2. Department of Pathology; Landspitali-University Hospital; Reykjavik Iceland
3. Department of Epidemiology and Biostatistics; VU University Medical Center; Amsterdam The Netherlands
4. Faculty of Medicine; University of Iceland; Reykjavik Iceland
5. Icelandic Cancer Registry; Icelandic Cancer Society; Reykjavik Iceland