Socioeconomic status and the incidence of non-central nervous system childhood embryonic tumours in Brazil
- Equal contributors
1 Pediatric Hematology and Oncology Program, Research Center, Instituto Nacional de Câncer, Rio de Janeiro, Brazil; Rua Andre Cavalcanti, 37, CEP 20231-050, Rio de Janeiro, Brazil
2 Coordenação de Prevenção e Vigilância, Instituto Nacional do Câncer, Rio de Janeiro, Rua dos Inválidos, 212, 3rd floor, CEP 20231-048, Brazil
3 Pediatric Department, Instituto Nacional de Câncer, Rio de Janeiro, Brazil, Praça Cruz Vermelha, Rio de Janeiro, Brazil
BMC Cancer 2011, 11:160 doi:10.1186/1471-2407-11-160Published: 5 May 2011
Childhood cancer differs from most common adult cancers, suggesting a distinct aetiology for some types of childhood cancer. Our objective in this study was to test the difference in incidence rates of 4 non-CNS embryonic tumours and their correlation with socioeconomic status (SES) in Brazil.
Data was obtained from 13 Brazilian population-based cancer registries (PBCRs) of neuroblastoma (NB), Wilms'tumour (WT), retinoblastoma (RB), and hepatoblastoma (HB). Incidence rates by tumour type, age, and gender were calculated per one million children. Correlations between social exclusion index (SEI) as an indicator of socioeconomic status (SES) and incidence rates was investigated using the Spearman's test.
WT, RB, and HB presented with the highest age-adjusted incidence rates (AAIRs) in 1 to 4 year old of both genders, whereas NB presented the highest AAIR in ≤11 month-olds. However, differences in the incidence rates among PBCRs were observed. Higher incidence rates were found for WT and RB, whereas lower incidence rates were observed for NB. Higher SEI was correlated with higher incidences of NB (0.731; p = 0.0117), whereas no SEI correlation was observed between incidence rates for WT, RB, and HB. In two Brazilian cities, the incidence rates of NB and RB were directly correlated with SEI; NB had the highest incidence rates (14.2, 95% CI, 8.6-19.7), and RB the lowest (3.5, 95% CI, 0.7-6.3) in Curitiba (SEI, 0.730). In Natal (SEI, 0.595), we observed just the opposite; the highest incidence rate was for RB and the lowest was for NB (4.6, 95% CI, 0.1-9.1).
Regional variations of SES and the incidence of embryonal tumours were observed, particularly incidence rates for NB and RB. Further studies are necessary to investigate risk factors for embryonic tumours in Brazil.