Trends in childhood leukemia mortality over a 25-year period

Objective: To analyze trends in childhood leukemia mortality in the state of Rio de Janeiro, Brazil, between 1980 and 2006. Method: Gender-stratified leukemia mortality data for children aged < 15 years from 1980 to 2006 were retrieved from the Brazilian Mortality Information System for the state of Rio de Janeiro. Data were stratified by place of death (city of Rio de Janeiro proper, the state capital; Rio de Janeiro Metropolitan Region, excluding the capital; and rest of the state). Leukemia deaths were defined according to death certificate ICD-9 and ICD-10 coding (for deaths occurring in 1980-1995 and 1996-2006, respectively). Leukemia mortality rates were calculated by age and calendar year and age-adjusted to a standard world population. Polynomial linear regression with a 5% significance level was used to evaluate mortality trends in the study regions. Results: The three studied regions revealed similar trends, with a continuous downward pattern; the most substantial decline was detected in the municipality of Rio de Janeiro (city proper). In all studied areas, leukemia mortality was highest among males. Conclusions: A downward trend in childhood leukemia mortality was detected throughout the state of Rio de Janeiro. The most pronounced reduction occurred in the state capital.