Prostate stem cell antigen polymorphisms and susceptibility to gastric cancer: a systematic review and meta-analysis

Many studies have reported that prostate stem cell antigen (PSCA) polymorphisms (rs2294008 and/or 2976392) are significantly associated with gastric cancer (GC) risk, although the published results are inconsistent. We conducted a systematic review and meta-analysis for relevant literatures to quantitatively evaluate the relationship between PSCA polymorphisms and GC susceptibility.

Extensive searches were conducted in three databases up to November 1, 2011. ORs and 95% CIs were used to assess the strength of the associations. The data were further stratified by ethnicity, histopathology, subsite, and study design. All of the associations were evaluated with dominant model and recessive model, respectively. Heterogeneity and publication bias were also assessed by Q test, I(2), and funnel plot accordingly.

Nine articles including 11 case-control data sets were included, with 10,746 GC cases and 9,158 controls for rs2294008 and 6,060 cases and 4,824 controls for rs2976392. The results showed that risk allele carriers were significantly associated with GC risk compared with nonrisk allele homozygotes. In stratification analyses, these associations remained significant for majority of subgroups except for Caucasians and noncardia tumor in dominant model, and cardia tumor in both dominant and recessive model. Random model was used when heterogeneity among studies was detected. No publication bias was observed.

The two loci of PSCA (rs2294008 and rs2976392) were both significantly associated with GC susceptibility and in linkage disequilibrium.

More prospective studies on PSCA polymorphisms at multicenters with sufficient sample size and less heterogeneity will be needed for further validations.