title: Childhood lymphoma incidence patterns by ICCC-3 subtype in Mexico City metropolitan area population insured by Instituto Mexicano del Seguro Social, 1996-2010.
abstract: OBJECTIVE
  We reviewed the childhood lymphomas epidemiological data for the Mexico City metropolitan area (MCMA).
  
  
  METHODS
  Data analysis from children (0-14 years old) diagnosed with lymphoma during the period 1996-2010 was performed at the Mexican Childhood Cancer Registry. Histological subtype was determined according to the International Classification of Childhood Cancer 3 (ICCC-3). Age-adjusted incidence rates were calculated per 1,000,000 children/year by age, gender, and ICCC-3 subtype; trends, by average annual percent change (AAPC).
  
  
  RESULTS
  A total of 328 lymphoma cases included in the study had an incidence rate of 11.8, showing a decreasing trend [AAPC: -3.5; CI 95% (-5.9, -1.0)], primarily due to non-Hodgkin lymphomas (NHL) and Hodgkin lymphoma (HL) mixed cellularity subtype. NHL had the major incidence (5.8), with the precursor cell subtype being the most frequent (38.3%). Nodular sclerosis was the most frequent HL subtype. The incidence of Burkitt lymphoma was low (1.3). During the study period, there was an important reduction in the not-otherwise-specified subtype of NHL, which translated into a relative increase in the IIb3 subtype [AAPC: 7.3 (1.2, 13.8)]. Low incidences of NHL and of HL and NHL were found for < 1-year-olds and for 10- to 14-year-olds, respectively. Incidence rates for children in the MCMA, particularly the < 1 and 10-14 age groups, were lower than those for developed countries. The overall male/female ratio was 2.3.
  
  
  CONCLUSIONS
  There was a trend toward a reduced incidence, for some lymphoma subtypes, in particular for NOS lymphomas, which may be the result of improvement in diagnostic techniques.
authors.affiliation: Unidad de Investigación en Epidemiología Clínica, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, D.F., Mexico.
authors.forename: Mario Enrique
authors.initials: ME
authors.lastname: Rendón-Macías
authors.forename: Edwin A
authors.initials: EA
authors.lastname: Valencia-Ramón
authors.forename: Arturo
authors.initials: A
authors.lastname: Fajardo-Gutiérrez
authors.forename: Estefanía
authors.initials: E
authors.lastname: Rivera-Flores
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008223:Lymphoma / Q000453:epidemiology* / Q000473:pathology; D008297:Male; D008800:Mexico / Q000453:epidemiology; D012042:Registries