Meta-analysis of GSTM1 and GSTT1 Polymorphisms and Riskof Nasopharyngeal Cancer

Abstract

<strong>Background:</strong> Studies of associations between genetic polymorphism of glutathione S-transferase M1 (GSTM1)and glutathione S-transferase T1 (GSTT1) with risk of nasopharyngeal cancer (NPC) have generated conflictingresults. Thus, a meta-analysis was performed to clarify the effects of GSTM1 and GSTT1 polymorphisms on therisk of developing NPC. Materials and <br /><strong>Methods</strong>: A literature search in two electronic databases namely PubMedand EMBASE up to December 2012 was conducted and eligible papers were finally selected based on the inclusionand exclusion criteria. The pooled odds ratio (OR) and presence of heterogeneity and publication bias in thosestudies were evaluated. <br /><strong>Results</strong>: A total of 9 studies concerning nasopharyngeal cancer were evaluated. Analysesof all relevant studies showed increased NPC risk to be significantly associated with the null genotypes of GSTMI(OR=1.43, 95%CI 1.24-1.66) and GSTT1 (OR=1.28, 95%CI=1.09-1.51). In addition, evidence of publication biaswas detected among the studies on GSTM1 polymorphism. <br /><strong>Conclusions</strong>: This meta-analysis demonstrated theGSTM1 and GSTT1 null genotypes are associated with an increased risk of NPC.