title: Evaluation of childhood acute leukemia incidence and underreporting in Brazil by capture-recapture methodology.
abstract: BACKGROUND
  Population-based cancer registries (PBCR) are important in cancer epidemiology as they provide the basis for monitoring cancer incidence. Childhood acute lymphoblastic leukemia (ALL) is said to have lower incidence in developing countries, which has implications for its pathogenesis, but there are few studies concerning the completeness of cancer registries in developing countries. This study analyzes the number of cases and incidence of childhood acute lymphoblastic leukemia in three different cities in Brazil and estimates underreporting cases and possible PBCR failures.
  
  
  METHODS
  We evaluated the completeness of PBCR and the incidence rates of childhood ALL from three different Brazilian cities using the two-source capture-recapture method. The sources used were a population-based registry and databases from a diagnosis reference laboratory in 2001 and the Chapman's formula was used to calculate the estimates.
  
  
  RESULTS
  The estimated incidence was 5.76, 6.32 and 5.48 per 100,000 inhabitants for Salvador, Recife and Belo Horizonte, respectively. The estimated completeness of childhood ALL in PBCRs was 15.5%, 35.4% and 29.2%, respectively, for Salvador, Recife and Belo Horizonte.
  
  
  CONCLUSIONS
  There was a high estimated underreporting of childhood leukemia cases in some Brazilian cities. The relationship between information systems and the capture-recapture method application improved epidemiological estimates. Childhood acute lymphoblastic leukemia incidence rates are similar to those of developed countries.
authors.affiliation: Instituto Nacional de Câncer, CEP, Rio de Janeiro, Brazil. azevedosilva.fernanda@gmail.com
authors.forename: Fernanda
authors.initials: F
authors.lastname: Azevedo-Silva
authors.forename: Rejane de Souza
authors.initials: Rde S
authors.lastname: Reis
authors.forename: Marceli de Oliveira
authors.initials: Mde O
authors.lastname: Santos
authors.forename: Ronir Raggio
authors.initials: RR
authors.lastname: Luiz
authors.forename: Maria S
authors.initials: MS
authors.lastname: Pombo-de-Oliveira
mesh_terms: D000293:Adolescent; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D018563:Disease Notification / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D011159:Population Surveillance; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000453:epidemiology*; D012042:Registries