1. Affiliations of authors: Division of Hematology/Oncology, The Hospital for Sick Children, 555 University Ave, Toronto, Ontario M5G 1XG, Canada
2. Department of Cancer Epidemiology and Prevention Research, CancerControl Alberta, Alberta Health Services, Holy Cross Centre, 2210 2 St SW, Calgary, Alberta T2S 3C3, Canada
3. Department of Pediatrics, McMaster University, 1200 Main St W, Hamilton, Ontario L8N 3Z5, Canada
4. Dana Farber Cancer Institute, 450 Brookline Ave, Boston, MA 02215, USA
5. Section of Cancer Surveillance, International Agency for Research on Cancer, 150 Cours Albert Thomas, Lyon 69008, France
6. Departments of Oncology and Community Health Sciences, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada