A population-based study of retinoblastoma incidence and survival in Argentine children

Background: An increased incidence of retinoblastoma in some developing countries has been reported but no conclusive data are available from population-based studies at national level.

Purpose: To report the incidence and survival of retinoblastoma in Argentina from the National Pediatric Cancer Registry (ROHA) and the influence of socio-economical indicators on outcome.

Procedure: Cases reported to the ROHA (2000-2009) were analyzed. Incidence rates were calculated using National Vital Statistics and survival was estimated. The extended human development index (EHDI) was used as a socio-economical indicator.

Results: With 438 patients reported, an incidence of 5.0 cases per million children 0-14 years old (95% CI 3.5-6.4) was calculated. Median age at diagnosis was significantly higher for children from provinces with lower EHDI; (24 vs. 35 months for unilateral, (P = 0.003) and 9 versus 11.5 months for bilateral retinoblastoma (P = 0.027). The 3-year probability of survival was 0.87 and 0.94 for unilateral and bilateral retinoblastoma, respectively. Residents in provinces with higher EHDI had a better 3-year survival (0.93 vs. 0.77 for lower EHDI, P < 0.0001). Probability of survival was higher for patients treated at tertiary level institutions (P = 0.0015). The combination of low EHDI residence province with no treatment at a tertiary institution was associated with the worst survival outcome. For both, unilateral and bilateral disease, children who died were in average diagnosed at older age.

Conclusions: The incidence of retinoblastoma in Argentina is comparable to that of developed countries. Retinoblastoma is diagnosed later and survival is lower in the less developed areas of the country.