Lack of association between glutathione S-transferase T1 gene polymorphism and laryngeal cancer susceptibility: a meta-analysis based on 2,124 cases and 2,059 controls

Studies investigating the association between glutathione S-transferase T1 (GSTT1) gene polymorphism and laryngeal cancer susceptibility have reported conflicting results. The aim of the present study was to conduct a meta-analysis assessing the possible association of GSTT1 gene polymorphism with laryngeal cancer risk. The relevant studies were identified through a search of PubMed, Embase, ISI Web of Knowledge and Chinese National Knowledge Infrastructure until May 2011. Twelve studies were included in the present meta-analysis, which described a total of 2124 laryngeal cancer cases and 2059 controls. The overall odds ratio (OR) for GSTT1 null genotype was 1.40 (95% CI = 0.90-2.16). When stratifying for race, the pooled ORs for GSTT1 null genotype were 1.07 (95% CI = 0.81-1.41) in Caucasians and 5.63 (95% CI = 1.00-31.83) in Asians. The pooled ORs for GSTT1 null genotype were 1.03 (95% CI = 0.71-1.49) in population-based studies and 2.39 (95% CI = 0.73-7.86) in hospital-based studies, stratifying for study design. This meta-analysis suggested that there was lack of association between GSTT1 gene polymorphism and laryngeal cancer risk. However, larger scale primary studies are still required to further evaluate the interaction of GSTT1 gene polymorphism with laryngeal cancer risk.