Association Between the GSTP1 Codon 105 Polymorphism and Gastric Cancer Risk: an Updated Meta-analysis

Objective: The current meta-analysis was performed to address a more accurate estimation of the associationbetween glutathione S-transferase P1 (GSTP1) codon 105 polymorphism and risk of gastric cancer (GC), whichhas been widely reported with conflicting results.
Methods: A comprehensive literature search was conductedto identify all the relevant studies. Fixed or random effect models were selected based on the heterogeneitytest. Publication bias was estimated using Begg’s funnel plots and Egger’s regression test.
Results: A total of 20studies containing 2,821 GC cases and 6,240 controls were finally included in the analyses. Overall, no significantassociation between GSTP1 polymorphism and GC risk was observed in worldwide populations. However,subgroup analysis stratified by ethnicity showed that GSTP1 polymorphism was significantly associated withincreased risk of GC in Asians (G vs. A, OR = 1.273, 95%CI=1.011-1.605; GG vs. AA, OR=2.103, 95%CI=1.197-3.387; GG vs. AA+AG, OR =2.103, 95%CI=1.186-3.414). In contrast, no significant association was found inCaucasians in any genetic models, except for with AG vs. AA (OR=0.791, 95%CI=0.669-0.936). Furthermore, theGSTP1 polymorphism was found to be significantly associated with GC in patients with H. pylori infection andin those with a cardiac GC. Subgroup analysis stratified by Lauren’s classification and smoking status showedno significant association with any genetic model. No studies were found to significantly influence the pooledeffects in each genetic mode, and no potential publication bias was detected.
Conclusions: This meta-analysissuggested that the GSTP1 polymorphism might be associated with increased risk of GC in Asians, while GSTP1heterozygote genotype seemed to be associated with reduced risk of GC. Since potential confounders could notbe ruled out completely, further studies are needed to confirm these results.