Association between Cytotoxic T-lymphocyte antigen 4 (CTLA-4) +49 G>A (rs231775) polymorphism and esophageal cancer: from a case-control study to a meta-analysis.

The aim of this study was to evaluate the association between CTLA-4 +49 G>A polymorphism and esophageal cancer (EC) susceptibility in a hospital based case-control study and a subsequent meta-analysis. We implemented genotyping analyses for CTLA-4 +49 G>A polymorphism with 629 esophageal squamous cell carcinoma cases and 686 controls in a Chinese Han population. Polymerase chain reaction ligase detection reaction (PCR-LDR) method was used to identify genotypes of CTLA-4 +49 G>A polymorphism. We first assessed the association between CTLA-4 +49 G>A polymorphism and EC risk in a hospital based case-control study, and then performed a comprehensive meta-analysis to derive a more precise estimation. Our results demonstrated that CTLA-4 +49 G>A polymorphism was not associated with EC risk. This case-control study and further meta-analysis, failed to identify the association between CTLA-4 +49 G>A polymorphism and EC risk. And additional, further well designed studies with large sample sizes and detailed gene-environment data are required.