Retinoblastoma Incidence Trends in Canada: A National Comprehensive Population-Based Study

Purpose: To determine the incidence rates and geographic distribution of retinoblastoma in Canada to aid cancer control programs. Methods: Patients with retinoblastoma whose data were available from the Canadian Cancer Registry (CCR) and Le Registre Quebecois Cancer (LRQC) were studied. Using third edition International Classification of Diseases for Oncology (ICD-0) codes, the authors examined the incidence rates and geographic distribution of patients with retinoblastoma between 1992 and 2010. Patient data including sex, age, and laterality of the retinoblastoma were analyzed. Results: Between 1992 and 2010 in Canada, the average annual incidence rate of retinoblastoma was 11.58 cases per 1 million children younger than 5 years (95% CI [confidence interval]: 10.48 to 12.76). The incidence rate was stable over time, with an average age at diagnosis of 2.30 +/- 6.85 years and no gender predilection. The laterality of the reported cases was 81.48% for unilateral cases and 18.52% for bilateral cases. Provincially, Nova Scotia had twice the national average and the highest incidence rates of retinoblastoma across the Canadian provinces. Conclusions:This is the first study to define the disease burden of retinoblastoma and to highlight important longitudinal, geographic, and spatial differences in the distribution of retinoblastoma in Canada between 1992 and 2010.The results of this study indicate continuity of clinical trends between Canada, the United States, and other developed countries.