Authors: Rami Darwich, Feras Ghazawi, Elham Rahme, Nebras Alghazawi, Denis Sasseville, Miguel N. Burnier, Ivan V. Litvinov

Author Disclosure Block: R. Darwich: None. F. Ghazawi: None. E. Rahme: None. N. Alghazawi: None. D. Sasseville: None. M.N. Burnier: None. I.V. Litvinov: None.

Abstract Body:

Purpose: escriptive demographic statistics are important components of effective cancer control programs. The current study was conducted to examine the epidemiology of retinoblastoma (RB) in Canada during the period of 1992-2010 using 2 distinct population-based databases. 

Study Design: Retrospective cross-sectional population-based study. Methods: We examined data on the incidence of RB using 2 distinct population-based cancer registeries (Canadian Cancer Registry (CCR) and Le Registre Québécois du Cancer) for the period of 1992-2010 using International Classification of Diseases for Oncology ICD-O-3 codes. Data on sex and age of patients and laterality of RB were analyzed. 

Results: There were 445 patients diagnosed with RB in Canada between 1992 and 2010. The average annual incidence rate of RB, for the period 1992-2010, was found to be 11.58 (95% CI 10.48-12.76) cases per million children under the age of 5 per year. Linear regression analyses of the RB incidence rates per million children younger than 5 years revealed no statistically significant changes in incidence during the study period (coefficient of determination [R2]= 0.08; p=0.60). The mean age ± standard deviation (SD) at the time of diagnosis was 2.35 ± 6.85 years, and the male-to-female incidence rate was 1:1.02 (M:F 220:225). The laterality of the reported cases of RB was found to be 81.48% for unilateral cases and 18.52% for bilateral cases. Provincially, Nova Scotia had an incidence rate of 23.93 (95% CI 14.62-36.96) which is up to three-fold the national average annual incidence rate. The incidence rates of RB across Canadian cities were comparable to the national average. 

Conclusions: Our findings indicate continuity of clinical trends between Canada, United States and other developed countries. This study will provide a foundation on which to monitor Canadian RB incidence patterns and can serve to further stimulate etiologic research.