GSTP1 exon 5 rs200139798 polymorphism and clinicopathological characteristics of gastric cancer in Chinese patients

This study was undertaken to detect the incidence of variations in exon 5 of GSTP1, a member of the glutathione-S-transferase family, in gastric cancer in relation to histological parameters. The study included 216 gastric cancers and 300 benign gastric diseases as controls. DNA was extracted from paraffin-embedded tissues and polymerase chain reaction-restriction fragment length polymorphism analysis was performed to examine the GSTP1 Ile105Val gene polymorphism in the study participants. A positive association between GSTP1 polymorphism and gastric cancer was observed in subjects carrying at least one G allele (AG and GG); the adjusted odds ratio (OR) for GSTP1 AA versus AG+GG was 1.416 (95% confidence interval [CI] 1.007 to 1.989, after controlling for age and gender). Patients over 50 years old more frequently carried the AG+GG genotype than those aged less than 50 (P=0.011) with adjusted OR (95% CI) of 2.758 (1.227-6.201). Compared with the well-differentiated group, the incidence of the GSTP1 AA genotype was decreased in the moderately [P=0.026; OR (95% CI)=3.559 (1.07211.813)] and poorly [P=0.003; OR (95% CI)=6.015 (1.679-21.549)] differentiated groups. The incidence of the GSTP1 AA genotype in intestinal type was higher than that in diffuse type (adjusted P=0.014; OR [95% CI]=2.210 [1.160-4.210]). All results indicated that the GSTP1 Ile105Val variant was closely associated with an increased risk of gastric cancer, and was significantly associated with patient age, tissue differentiation degree, and Lauren classification but not with gender, gross classification, tumor size (diameter), infiltration depth, and lymph node involvement.