title: Atopic conditions and brain tumor risk in children and adolescents--an international case-control study (CEFALO).
abstract: BACKGROUND
  A number of epidemiological studies indicate an inverse association between atopy and brain tumors in adults, particularly gliomas. We investigated the association between atopic disorders and intracranial brain tumors in children and adolescents, using international collaborative CEFALO data.
  
  
  METHODS
  CEFALO is a population-based case-control study conducted in Denmark, Norway, Sweden, and Switzerland, including all children and adolescents in the age range 7-19 years diagnosed with a primary brain tumor between 2004 and 2008. Two controls per case were randomly selected from population registers matched on age, sex, and geographic region. Information about atopic conditions and potential confounders was collected through personal interviews.
  
  
  RESULTS
  In total, 352 cases (83%) and 646 controls (71%) participated in the study. For all brain tumors combined, there was no association between ever having had an atopic disorder and brain tumor risk [odds ratio 1.03; 95% confidence interval (CI) 0.70-1.34]. The OR was 0.76 (95% CI 0.53-1.11) for a current atopic condition (in the year before diagnosis) and 1.22 (95% CI 0.86-1.74) for an atopic condition in the past. Similar results were observed for glioma.
  
  
  CONCLUSIONS
  There was no association between atopic conditions and risk of all brain tumors combined or of glioma in particular. Stratification on current or past atopic conditions suggested the possibility of reverse causality, but may also the result of random variation because of small numbers in subgroups. In addition, an ongoing tumor treatment may affect the manifestation of atopic conditions, which could possibly affect recall when reporting about a history of atopic diseases. Only a few studies on atopic conditions and pediatric brain tumors are currently available, and the evidence is conflicting.
authors.affiliation: Unit of Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm. Electronic address: xiaochen.shu@ki.se.
authors.forename: X
authors.initials: X
authors.lastname: Shu
authors.affiliation: Unit of Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm.
authors.forename: M
authors.initials: M
authors.lastname: Prochazka
authors.affiliation: Department of Pediatrics, University of Gothenburg, The Queen Silvia Children's Hospital, Gothenburg, Sweden.
authors.forename: B
authors.initials: B
authors.lastname: Lannering
authors.affiliation: Danish Cancer Society Research Center, Copenhagen, Denmark; International Agency for Research on Cancer (IARC), Section of Environment and Radiation, Lyon, France.
authors.forename: J
authors.initials: J
authors.lastname: Schüz
authors.affiliation: Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel; University of Basel, Basel, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Röösli
authors.affiliation: The Cancer Registry of Norway, Oslo; National Institute of Occupational Health, Oslo, Norway.
authors.forename: T
authors.initials: T
authors.lastname: Tynes
authors.affiliation: Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland.
authors.forename: C E
authors.initials: CE
authors.lastname: Kuehni
authors.affiliation: Danish Cancer Society Research Center, Copenhagen, Denmark.
authors.forename: T V
authors.initials: TV
authors.lastname: Andersen
authors.affiliation: Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel; University of Basel, Basel, Switzerland.
authors.forename: D
authors.initials: D
authors.lastname: Infanger
authors.affiliation: Danish Cancer Society Research Center, Copenhagen, Denmark.
authors.forename: L S
authors.initials: LS
authors.lastname: Schmidt
authors.affiliation: Danish Cancer Society Research Center, Copenhagen, Denmark.
authors.forename: A H
authors.initials: AH
authors.lastname: Poulsen
authors.affiliation: The Cancer Registry of Norway, Oslo; Norwegian Radiation Protection Authority, Oslo, Norway.
authors.forename: L
authors.initials: L
authors.lastname: Klaeboe
authors.affiliation: The Cancer Registry of Norway, Oslo.
authors.forename: T
authors.initials: T
authors.lastname: Eggen
authors.affiliation: Unit of Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm.
authors.forename: M
authors.initials: M
authors.lastname: Feychting
mesh_terms: D000293:Adolescent; D000328:Adult; D001932:Brain Neoplasms / Q000150:complications / Q000453:epidemiology* / Q000473:pathology; D016022:Case-Control Studies; D002648:Child; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005910:Glioma / Q000150:complications / Q000453:epidemiology* / Q000473:pathology; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000150:complications / Q000453:epidemiology* / Q000473:pathology; D008297:Male; D012307:Risk Factors; D055815:Young Adult
keywords: allergy; brain tumors; case–control study; childhood; glioma