title: Epidemiological and some clinical characteristics of neuroblastoma in Mexican children (1996-2005).
abstract: BACKGROUND
  Neuroblastoma (NB) is the principal tumor of the sympathetic nervous system in children under one year of age. The incidence in developed countries is greater than that in developing countries. The aim of this article is to present the epidemiological and some clinical characteristics of Mexican children with NB.
  
  
  METHODS
  A population-based, prolective study, with data obtained from the Childhood Cancer Registry of the Instituto Mexicano de Seguro Social.
  
  
  METHODS
  The simple frequencies of the variables of the study and the annual average incidence (per 1,000,000 children/years) by age and sex were obtained. The trend was evaluated by calculating the annual percentage of change. The curves of Kaplan-Meyer were employed for the survival rate and the log-rank test was used to compare the curves.
  
  
  RESULTS
  Of a total of 2,758 children with cancer registered during the period from 1996-2005, 72 (2.6%) were identified as having Group IV, defined according to the International Classification of Childhood Cancer. The incidence for NB was 3.8 per 1,000,000 children/year; NB was highest in the group of children under one year of age, followed by the group of children between the ages 1-4 years (18.5 and 5.4 per 1,000,000 children/years, respectively). The male/female ratio was 1.1 and there was no trend toward an increase. The time of diagnosis was 26 days (median), but varied according to the stage at diagnosis. Stages III and IV were presented in 88% of the cases. There was no association between the stage, the age at time of diagnosis, or the histological pattern. The overall five-year survival rate was 64%; the patients with stage I, II, III, or IVs did not die; and the five-year survival rate of cases in Stage IV was 40%.
  
  
  CONCLUSIONS
  It is possible that the low incidence of neuroblastoma in Mexican children is due to the difficulty in diagnosing the cases with the best prognosis, some of which could have had spontaneous regression. There was no trend to an increase; the majority of the cases were diagnosed in the advanced stages; and the overall five-years survival rate was similar to that for developed countries.
authors: Unidad de Investigación Médica en Epidemiología Clínica, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Ciudad de México, México. servando_juarez@yahoo.com.mx
authors: Servando
authors: S
authors: Juárez-Ocaña
authors: Virginia
authors: V
authors: Palma-Padilla
authors: Guadalupe
authors: G
authors: González-Miranda
authors: Alicia Georgina
authors: AG
authors: Siordia-Reyes
authors: Enrique
authors: E
authors: López-Aguilar
authors: Martha
authors: M
authors: Aguilar-Martínez
authors: Juan Manuel
authors: JM
authors: Mejía-Aranguré
authors: Rogelio
authors: R
authors: Carreón-Cruz
authors: Mario Enrique
authors: ME
authors: Rendón-Macías
authors: Arturo
authors: A
authors: Fajardo-Gutiérrez
mesh_terms: D000293:Adolescent; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008800:Mexico; D009447:Neuroblastoma / Q000175:diagnosis* / Q000453:epidemiology*; D012074:Remission Induction; D013997:Time Factors; D016896:Treatment Outcome