title: Immune-related conditions and subsequent risk of brain cancer in a cohort of 4.5 million male US veterans.
abstract: BACKGROUND
  Case-control studies have reported an inverse association between self-reported history of allergy and risk of glioma, but cohort data are limited. Our objectives were to evaluate the associations of major groups of medically diagnosed immune-related conditions (allergy/atopy, autoimmune disease, diabetes, infectious/inflammatory disease) and to explore associations with specific conditions in relation to subsequent diagnosis of brain cancer in a large cohort study.
  
  
  METHODS
  We used hospital discharge records for a cohort of 4.5 million male US veterans, of whom 4383 developed primary brain cancer. Rate ratios (RRs) and 95% confidence intervals (CIs) were calculated using time-dependent Poisson regression.
  
  
  RESULTS
  We found a significant trend of decreasing RRs for brain cancer with longer duration of allergy/atopy (P=0.02), but not for other conditions studied. Rate ratios of brain cancer for allergy/atopy and diabetes with duration of 10 or more years were 0.60 (95% CI: 0.43, 0.83) and 0.75 (95% CI: 0.62, 0.93), respectively. Several associations with specific conditions were found, but these did not withstand correction for multiple comparisons.
  
  
  CONCLUSIONS
  This study lends some support to an inverse association between allergy/atopy and diabetes of long duration and brain cancer risk, but prospective studies with biological samples are needed to uncover the underlying biological mechanisms.
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20850, USA.
authors.forename: E K
authors.initials: EK
authors.lastname: Cahoon
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20850, USA.
authors.forename: P D
authors.initials: PD
authors.lastname: Inskip
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20850, USA.
authors.forename: G
authors.initials: G
authors.lastname: Gridley
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20850, USA.
authors.forename: A V
authors.initials: AV
authors.lastname: Brenner
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000453:epidemiology*; D016022:Case-Control Studies; D015331:Cohort Studies; D006801:Humans; D007154:Immune System Diseases / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D014728:Veterans / Q000706:statistics & numerical data*; D055815:Young Adult