GSTM1 polymorphism is related to risks of nasopharyngeal cancer and laryngeal cancer: a meta-analysis.

BACKGROUND: Accumulating data have reported that GSTM1 polymorphism may be related to nasopharyngeal cancer (NPC) and laryngeal cancer (LC). This meta-analysis was performed to investigate the relationship between GSTM1 polymorphism and risks of NPC and LC. METHODS: Pubmed, Embase, and China National Knowledge Infrastructure (CNKI) databases were searched for potential articles. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the relationship of GSTM1 polymorphism with the risks of NPC and LC. I2>50% or P<0.05 indicates significant heterogeneity. When heterogeneity existed, the random-effects model was used to pool data, otherwise, the fixed-effects model was adopted. Publication bias was detected by Begg's funnel plot and Egger's regression. Quality of each study was evaluated by Newcastle-Ottawa Scale. RESULTS: Thirty-two eligible articles were included. Pooled outcome suggested the significant relationship of GSTM1 null genotype with increased risk of LC (OR =1.28, 95% CI =1.05-1.54). Compared with hospital-based (HB) population, GSTM1 null genotype was also related to increased risk of LC (OR =1.38, 95% CI =1.06-1.80). Positive relationship of GSTM1 null genotype with enhanced risk of NPC was observed (OR =1.43, 95% CI =1.26-1.63). A similar trend was also observed in the subgroup analysis by source of control (population-based [PB]: OR =1.39, 95% CI =1.18-1.63; HB: OR =1.52, 95% CI =1.22-1.89). CONCLUSION: GSTM1 null genotype is related to increased risk of NPC and LC.