title: Risk factors for oligodendroglial tumors: a pooled international study.
abstract: Oligodendroglial tumors are rare subtypes of brain tumors and are often combined with other glial tumors in epidemiological analyses. However, different demographic associations and clinical characteristics suggest potentially different risk factors. The purpose of this study was to investigate possible risk factors for oligodendroglial tumors (including oligodendroglioma, anaplastic oligodendroglioma, and mixed glioma). Data from 7 case-control studies (5 US and 2 Scandinavian) were pooled. Unconditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs), adjusted for age group, gender, and study site. Data on 617 cases and 1260 controls were available for analyses. Using data from all 7 studies, history of allergies and/or asthma was associated with a decreased risk of anaplastic oligodendroglioma (OR = 0.6; 95% CI: 0.4-0.9), and history of asthma only was associated with a decreased risk of oligodendroglioma (OR = 0.5; 95% CI: 0.3-0.9) and anaplastic oligodendroglioma (OR = 0.3; 95% CI: 0.1-0.9). A family history of brain tumors was associated with an increased risk of anaplastic oligodendroglioma (OR = 2.2; 95% CI: 1.1-4.5). Having had chicken pox was associated with a decreased risk of oligodendroglioma (OR = 0.6; 95% CI: 0.4-0.9) and anaplastic oligodendroglioma (OR = 0.5; 95% CI: 0.3-0.9) in the US studies. Although there is some overlap in risk factors between oligodendroglial tumors and gliomas as a group, it is likely that additional factors specific to oligodendroglial tumors have yet to be identified. Large, multi-institution international studies will be necessary to better characterize these etiological risk factors.
authors.affiliation: Department of Epidemiology/Biostatistics, School of Public Health, University of Illinois at Chicago, 1603 W. Taylor St. (M/C 923), Chicago, IL 60612, USA. bjm3@uic.edu
authors.forename: Bridget J
authors.initials: BJ
authors.lastname: McCarthy
authors.forename: Kristin M
authors.initials: KM
authors.lastname: Rankin
authors.forename: Ken
authors.initials: K
authors.lastname: Aldape
authors.forename: Melissa L
authors.initials: ML
authors.lastname: Bondy
authors.forename: Thomas
authors.initials: T
authors.lastname: Brännström
authors.forename: Helle
authors.initials: H
authors.lastname: Broholm
authors.forename: Maria
authors.initials: M
authors.lastname: Feychting
authors.forename: Dora
authors.initials: D
authors.lastname: Il'yasova
authors.forename: Peter D
authors.initials: PD
authors.lastname: Inskip
authors.forename: Christoffer
authors.initials: C
authors.lastname: Johansen
authors.forename: Beatrice S
authors.initials: BS
authors.lastname: Melin
authors.forename: Avima M
authors.initials: AM
authors.lastname: Ruder
authors.forename: Mary Ann
authors.initials: MA
authors.lastname: Butler
authors.forename: Michael E
authors.initials: ME
authors.lastname: Scheurer
authors.forename: Joachim
authors.initials: J
authors.lastname: Schüz
authors.forename: Judith A
authors.initials: JA
authors.lastname: Schwartzbaum
authors.forename: Margaret R
authors.initials: MR
authors.lastname: Wrensch
authors.forename: Faith G
authors.initials: FG
authors.lastname: Davis
mesh_terms: D000328:Adult; D001932:Brain Neoplasms / Q000453:epidemiology*; D016022:Case-Control Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D007390:International Agencies; D008297:Male; D015201:Meta-Analysis as Topic; D008875:Middle Aged; D009837:Oligodendroglioma / Q000453:epidemiology*; D011379:Prognosis; D012307:Risk Factors; D015996:Survival Rate; D013548:Sweden / Q000453:epidemiology; D014481:United States / Q000453:epidemiology