GSTM1 null genotype may be associated with an increased nasopharyngeal cancer risk in South China: an updated meta-analysis and review

Although many epidemiologic studies investigated the GSTM1 gene polymorphism and its association with nasopharyngeal carcinoma (NPC) in Chinese, definite conclusions cannot be drawn. To assess the impact of of GSTM1 polymorphism on the risk of NPC, an updated meta-analysis was performed in a Chinese population. A total of nine studies including 1,291 cases and 2,135 controls were involved in this meta-analysis. Meta-analysis of those nine studies showed that GSTM1 null genotype was associated with an increased risk of NPC in South China (odds ratio [OR] =1.47, 95% confidence interval [CI]: 1.27-1.70). In subgroup analyses stratified by source of controls, it revealed significant results in population-based studies (OR =1.40, 95% CI: 1.19-1.64). Additionally, a significant association was found in smokers (OR =3.16, 95% CI: 1.76-5.67). This meta-analysis indicated a marked association of GSTM1 with NPC risk in South China, and there might be an interaction between the polymorphism and smoking on NPC. However, further studies with gene-gene and gene-environment interactions are required for definite conclusions.