Lymphoma subtype incidence rates in children and adolescents: first report from Brazil

Lymphoma is the third most common pediatric malignancy. The purpose of this study was to analyze the incidence rates of lymphoma in children and adolescents in Brazil.

All cases of Hodgkin lymphoma (HL), non-Hodgkin lymphoma (NHL), and Burkitt lymphoma (BL) were extracted from 14 population-based cancer registries (PBCRs) from 2000 to 2005, and included children and adolescents 0-19 years old. Analyses included age-adjusted incidence rates (AAIRs) and age-specific incidence rates (ASIRs) by each PBCR. A social exclusion index (SEI) was built and used as proxy for socioeconomic status (SES) levels. Correlations between SES and incidence rates were investigated using Spearman's test.

The median incidence of lymphoma was 22.7/million. AAIRs of lymphomas varied from 12.9 (Salvador) to 34.5 per million (São Paulo). Median AAIR was 8.8/million, 9.8/million, and 2.9/million for NHL, HL, and BL, respectively. In all PBCRs except that of Recife, AAIR was slightly higher in males than females. The median ASIR was highest for HL (18.5/million) at 15-19 years for both genders. For NHL there were two peaks for ASIR: 11.1/million (1-4 years of age) and 13.2/million (15-19 years of age). The median ASIR for BL was highest among children aged 1-4 years (4.7/million) and in males. Higher SEI correlated with higher incidence of HL (P = 0.06), whereas rates of NHL and BL did not correlate with SEI. Borderline different incidence rates were observed in HL correlated with cities with higher SEIs.

Incidence rates of lymphomas in Brazil do not differ compared to rates reported worldwide, although SES differences deserve further investigation.