1. Department of Women's and Children's Health Childhood Cancer Research Unit Karolinska Institute Stockholm Sweden
2. Department of Pediatric Oncology Karolinska University Hospital Stockholm Sweden
3. Department of Health Care Sciences Palliative Research Centre Ersta Sköndal Bräcke University College Stockholm Sweden
4. Department of Paediatrics and Adolescent Medicine Aarhus University Hospital Aarhus Denmark
5. Institute of Clinical Medicine Faculty of Health University of Aarhus Aarhus Denmark
6. Pediatric and Adolescent Hematology/Oncology Turku University Hospital Fican‐West and Turku University Turku Finland
7. Swedish Childhood Cancer Registry Karolinska Institutet Stockholm Sweden
8. Department of Women's and Children's Health Uppsala University and Pediatric Oncology Uppsala University Hospital Uppsala Sweden