title: Does smoking increase the risk of developing glioma? A meta-analysis based on case-control studies.
abstract: OBJECTIVE
  The purpose of this study was to assess the relationship between smoking and glioma risk by meta-analysis.
  
  
  METHODS
  We have searched the databases of MEDLINE, EMBASE, Ovid, and CNKI to find the suitable studies related to association between smoking and glioma risk. The pooled odds ratio (OR) and 95% confidence interval (CI) of smokers in glioma patients compared to normal controls were aggregated by statistic software Stata11.0. The publication bias was evaluated by Begg's funnel plot.
  
  
  RESULTS
  Finally, seven case-control studies were included in this meta-analysis. The pooled results showed that smoking did not increase the risk of glioma (OR = 0.96, 95% CI = 0.86-1.07, P > 0.05).
  
  
  CONCLUSIONS
  No close association between smoking and glioma risk was found in this meta-analysis, which indicate that smoking may not contribute to the incidence of glioma.
authors.affiliation: Department of Neurology, Henan University Huaihe Hospital, Kaifeng, Henan, P.R. China.
authors.forename: Xiaqing
authors.initials: X
authors.lastname: Guo
authors.affiliation: Department of Neurology, Henan University Huaihe Hospital, Kaifeng, Henan, P.R. China.
authors.forename: Yabo
authors.initials: Y
authors.lastname: Wang
mesh_terms: D001932:Brain Neoplasms / Q000453:epidemiology / Q000209:etiology*; D016022:Case-Control Studies; D005910:Glioma / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D016017:Odds Ratio; D017594:Publication Bias; D012306:Risk; D012907:Smoking / Q000009:adverse effects*