1. Finnish Cancer Registry Helsinki Finland
2. Children and Adolescents Helsinki University Hospital and University of Helsinki Helsinki Finland
3. Childhood Cancer Research Group Danish Cancer Society Research Center Copenhagen Denmark
4. Division of Childhood Cancer Epidemiology Institute of Medical Biostatistics, Epidemiology, and Informatics (IMBEI), University Medical Center of the Johannes Gutenberg University Mainz Germany
5. Department of Prevention and Evaluation Leibniz Institute for Prevention Research and Epidemiology – BIPS Bremen Germany
6. Unit of Epidemiology Institute of Environmental Medicine, Karolinska Institutet Stockholm Sweden
7. Childhood Cancer Research Group Institute of Social and Preventive Medicine, University of Bern Bern Switzerland
8. Cancer Registry Bern‐Solothurn University of Bern Bern Switzerland
9. Division of Pediatric Hematology, Oncology, and Stem Cell Transplantation Helsinki University Hospital Helsinki Finland
10. Dana Farber/Boston Children's Cancer and Blood Disorders Clinic Boston Massachusetts USA
11. Health Sciences Unit, Faculty of Social Sciences Tampere University Tampere Finland
12. Department of Public Health, Faculty of Medicine University of Helsinki Helsinki Finland