Trends in incidence of childhood cancer in Canada, 1992-2006.

INTRODUCTION Cancer is the leading cause of disease-related death in children aged 1 to 14 years in Canada. Despite the importance to public health of childhood cancer, there have been few reports on Canadian trends published in the peer-reviewed literature. This study examines childhood cancer trends by age, sex, and province of residence using the most current cancer registration data. METHODS Data from the population-based Canadian Cancer Registry were used to compute incidence trends in primary cancers diagnosed between 1992 and 2006 in children (0-14 years) for the 12 major diagnostic groups of the International Classification of Childhood Cancer, 3rd Edition. RESULTS Between 1992 and 2006, incidence rates for all cancers remained stable, although trends varied by cancer type. We observed a significant decrease in retinoblastoma in boys for the entire period (-6.5% per year) and an increase in leukemia from 1992 to 1999 (+3.5% per year). In girls, there was a significant decrease in renal tumours from 1998 to 2006 (-5.7% per year) and an increase in hepatic tumours from 1997 to 2006 (+8.1% per year). Differences by age and province were also apparent. Some caution should be exercised when interpreting trends involving a small number of cases per year and those with wide 95% confidence intervals. CONCLUSIONS Our findings suggest an ongoing need for population-based surveillance and etiologic research.