title: Childhood cancer incidence in relation to sunlight exposure.
abstract: BACKGROUND
  There is increasing interest in the possible association between cancer incidence and vitamin D through its role as a regulator of cell growth and differentiation. Epidemiological studies in adults and one paediatric study suggest an inverse association between sunlight exposure and cancer incidence.
  
  
  METHODS
  We carried out an ecological study using childhood cancer registry data and two population-level surrogates of sunlight exposure, (1) latitude of the registry city or population centroid of the registry nation and (2) annual solar radiation. All models were adjusted for nation-level socioeconomic status using socioeconomic indicators.
  
  
  RESULTS
  Latitude and radiation were significantly associated with cancer incidence, and the direction of association was consistent between the surrogates. Findings were not consistent across tumour types.
  
  
  CONCLUSIONS
  Our ecological study offers some evidence to support an association between sunlight exposure and risk of childhood cancer.
authors.affiliation: Division of Pediatrics, Department of Epidemiology and Clinical Research, University of Minnesota, Minneapolis, MN 55455, USA. bruce087@umn.edu
authors.forename: J R B
authors.initials: JR
authors.lastname: Musselman
authors.forename: L G
authors.initials: LG
authors.lastname: Spector
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009381:Neoplasms, Radiation-Induced / Q000209:etiology*; D011379:Prognosis; D012042:Registries; D012307:Risk Factors; D012959:Socioeconomic Factors; D013472:Sunlight / Q000009:adverse effects*; D055815:Young Adult