Glutathione S-transferase M1 null genotype contributes to increased risk of esophageal carcinoma in Chinese population.

Glutathione S-transferases (GSTs) play important roles in the detoxification of electrophilic carcinogens, and GSTM1 null genotype is associated with the dysfunction of GSTs. Previous studies investigating the association between GSTM1 null genotype and risk of esophageal carcinoma in Chinese provided inconsistent findings. To provide a more precise estimation on the association between GSTM1 null genotype and risk of esophageal carcinoma in Chinese population, a meta-analysis was performed. Eligible studies were searched in PubMed, Embase, and China National Knowledge Infrastructure databases. Odds ratio (OR) with the corresponding 95 % confidence interval (95 %CI) was used to assess the association. A total of 18 case-control studies involving 1,947 cases and 3,506 controls were finally included in the meta-analysis. Meta-analysis of those 18 studies showed that GSTM1 null genotype was associated with an increased risk of esophageal carcinoma in Chinese (random effect model OR = 1.49, 95 %CI = 1.11-2.00, P = 0.008). The findings from cumulative meta-analysis showed that the association was more obvious as the data increased by publication year. There was no risk of publication bias in the meta-analysis. Therefore, the findings from our meta-analysis provide a strong evidence for the association between GSTM1 null genotype and risk of esophageal carcinoma in Chinese population, and GSTM1 null genotype contributes to increased risk of esophageal carcinoma in Chinese.