1. Faculty of Health Sciences and Medicine, University of Lucerne, Alpenquai 4, 6005 Lucerne, Switzerland
2. Cancer Registry of Central Switzerland, 6000 Lucerne, Switzerland
3. Division of Hematology & Oncology, Children’s Hospital of Eastern Switzerland, 9006 St. Gallen, Switzerland
4. Department of Pediatrics, McMaster Children’s Hospital and McMaster University, Hamilton, ON L8N 3Z5, Canada
5. Institute of Social and Preventive Medicine, University of Bern, 3012 Bern, Switzerland
6. Cancer Registry Bern-Solothurn, University of Bern, 3008 Bern, Switzerland