Background: Globally, retinoblastoma is the most common primary intraocular malignancy occurring inchildren. This paper documents the recent incidence rates of retinoblastoma by age and sex groups from thePopulation Based Cancer Registries (PBCRs) of Bangalore, Mumbai, Chennai, Delhi and Kolkata using thedata from the National Cancer Registry Programme. Materials and
Methods: Relative proportions, sex ratio,method of diagnosis, and incidence rates (crude and age standardized) for each PBCR and pooled rates of thefive PBCRs were calculated for the years 2005/06 to 2009/10. Standard errors and 95% confidence limits ofASIRs by sex group in each PBCR were calculated using the Poisson distribution. Standardised rate ratios ofASIR by sex group and rate ratios at risk were also calculated.
Results: The maximum retinoblastoma caseswere in the 0-4 age group, accounting for 78% (females) and 81% (males) of pooled cases from five PBCRs. Thepooled crude incidence rate in the 0-14 age group was 3.5 and the pooled ASIR was 4.4 per million. The pooledASIR in the 0-4, 5-9 and 10-14 age group were 9.6, 2.0 and 0.1 respectively. The M/F ratio in Chennai (1.9) andBangalore PBCRs (2.0) was much higher than the other PBCRs. Among the PBCRs, the highest incidence ratein 0-4 age group was found in males in Chennai (21.7 per million), and females in Kolkata (18.9 per million).There was a distinct variation in incidence rates in the PBCRs in different geographic regions of India.