Genetic variations of prostate stem cell antigen (PSCA) contribute to the risk of gastric cancer for Eastern Asians: a meta-analysis based on 16792 individuals.

The associations between polymorphisms of prostate stem cell antigen (PSCA-rs2294008C>T and -rs2976392G>A) and gastric cancer (GC) risk for Eastern Asians have been commonly studied, but the results were conflicting. The aim of the present study was to further assess the associations by the method of meta-analysis. The databases of Medline, Embase and CNKI (up to May 25th, 2011) were retrieved to identify eligible case-control studies. Odds ratio (OR) and 95% confidence interval (95%CI) were used to present the strength of the associations. In total, eight case-control studies in seven articles with 16792 individuals (9738 cases of GC and 7054 controls) were included in this meta-analysis. Through quantitative analyses, we found that T allele of rs2294008C>T and A allele of rs2976392G>A were significantly associated with increased GC risk [rs2294008C>T: OR (95%CI)=1.31 (1.22-1.42), P(z-test)<0.001, P(heterogeneity)=0.166 for TT vs. C carriers; rs2976392G>A: OR (95%CI)=1.36(1.24-1.50), P(z-test)=0.015, P(heterogeneity)=0.111 for AA vs. G carriers]. The results of subgroup analyses (according to histopathology, countries and sources of controls) indicated that T allele of rs2294008C>T and A allele rs2976392G>A were associated with increased risk of both intestinal- and diffuse-type GC, and associated with increased risk of GC for Chinese, Japanese, Koreans, PCC and HCC/PHCC. Furthermore, T allele of rs2294008C>T was also associated with increased risk of cardia and non-cardia GC, and associated with increased risk of GC for males and females. Besides those, this meta-analysis also indicated that the interactions between T allele of rs2294008C>T and A allele of rs2976392G>A was associated with increased risk of GC (A-T vs. G-T: OR=1.16, 95%CI=1.06-1.27, P(z-test)=0.001, P(heterogeneity)=0.835). Although modest limitations and potential bias cannot be eliminated, this meta-analysis suggests that PSCA -rs2294008C>T and -rs2976392G>A are potential factors of GC development for Eastern Asians, and future work may incorporate these findings and evaluate these variants as potential markers for screening and early diagnosis of GC.