Does smoking increase the risk of developing glioma? A meta-analysis based on case-control studies.

OBJECTIVE: The purpose of this study was to assess the relationship between smoking and glioma risk by meta-analysis.

MATERIALS AND 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).

CONCLUSION: 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.