title: Race/ethnicity and the risk of childhood leukaemia: a case-control study in California.
abstract: BACKGROUND
  We conducted a large registry-based study in California to investigate the association between race/ethnicity and childhood leukaemia focusing on two subtypes: acute lymphoblastic leukaemia (ALL) and acute myeloid leukaemia (AML).
  
  
  METHODS
  We obtained information on 5788 cases and 5788 controls by linking California cancer and birth registries. We evaluated relative risk of childhood leukaemia by race and ethnicity of the child and their parents using conditional logistic regression, with adjustment for potential confounders.
  
  
  RESULTS
  Compared with Whites, Black children had lower risk of ALL (OR=0.54, 95% CI 0.45 to 0.66) as well as children of Black/Asian parents (OR=0.31, 95% CI 0.10 to 0.94). Asian race was associated with increased risk of AML with OR=1.643, 95% CI 1.10 to 2.46 for Asian vs Whites; and OR=1.67, 95% CI 1.04 to 2.70 for Asian/Asian vs White/White. Hispanic ethnicity was associated with increased risk of ALL (OR=1.37, 95% CI 1.22 to 1.52). A gradient in risk of ALL was observed while comparing Hispanic children with both parents Hispanic, one parent Hispanic and non-Hispanic children (p Value for trend <0.0001). The highest risk of ALL was observed for children with a combination of Hispanic ethnicity and White race compared with non-Hispanic whites (OR=1.27, 95% CI 1.12 to 1.44). The lowest risk was observed for non-Hispanic blacks (OR=0.46, 95% CI 0.36 to 0.60). Associations for total childhood leukaemia were similar to ALL.
  
  
  CONCLUSIONS
  Our results confirm that there are ethnic and racial differences in the incidence of childhood leukaemia. These differences indicate that some genetic and/or environmental/cultural factors are involved in aetiology of childhood leukaemia.
authors: Department of Epidemiology, UCLA Fielding School of Public Health, Los Angeles, California, USA.
authors: Sona
authors: S
authors: Oksuzyan
authors: Department of Biostatistics, UCLA Fielding School of Public Health, Los Angeles, California, USA.
authors: Catherine M
authors: CM
authors: Crespi
authors: Department of Preventive Medicine, University of Southern California, Los Angeles, California, USA.
authors: Myles
authors: M
authors: Cockburn
authors: Department of Epidemiology and Computational Biology, Exponent Engineering and Scientific Consulting, Menlo Park, California, USA.
authors: Gabor
authors: G
authors: Mezei
authors: Environment Department, Electric Power Research Institute, Palo Alto, California, USA.
authors: Ximena
authors: X
authors: Vergara
authors: Department of Epidemiology, UCLA Fielding School of Public Health, Los Angeles, California, USA.
authors: Leeka
authors: L
authors: Kheifets
mesh_terms: D000293:Adolescent; D001741:Black or African American / Q000706:statistics & numerical data; D001213:Asian / Q000706:statistics & numerical data; D002140:California / Q000453:epidemiology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005006:Ethnicity / Q000706:statistics & numerical data*; D005260:Female; D006630:Hispanic or Latino / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D007198:Indians, North American / Q000706:statistics & numerical data; D007223:Infant; D007231:Infant, Newborn; D015470:Leukemia, Myeloid, Acute / Q000208:ethnology*; D016015:Logistic Models; D008297:Male; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000208:ethnology*; D012042:Registries; D012306:Risk; D044465:White People / Q000706:statistics & numerical data
keywords: CANCER; EPIDEMIOLOGY; ETHNICITY; PAEDIATRIC