Meta-analysis of the cytotoxic T-lymphocyte antigen 4 gene +6230G/A polymorphism and cancer risk

Abstract

Cytotoxic T-lymphocyte antigen-4 (CTLA4, CD152) is one of the most fundamental immunosuppressive cytokines that inhibits T-cell activation and terminates the T-cell response by blocking signals stimulated via CD28. A number of studies have assessed the association between CTLA-4 +6230G/A polymorphism and cancer risk. However, the results remain controversial. In the present study, we performed a meta-analysis to derive a more precise estimation of the relationship. A comprehensive literature search was performed using the PubMed database for relevant articles published (updated to November 21, 2013). Odds ratios (ORs) and 95 % confidence intervals (CIs) were used to assess the strength of the association. A total of 13 articles with 14 studies were selected for this meta-analysis, including 4,489 cases and 4,715 controls. Combined analysis revealed no associations between CTLA-4 +6230G/A polymorphism and cancer risk. However, in stratified analysis by cancer type, we found that CTLA-4 +6230G/A polymorphism was associated with the risk of breast cancer (AA vs. AG + GG: OR = 0.77, 95 % CI 0.60-0.97, P = 0.03; AA vs. GG: OR = 0.66, 95 % CI 0.46-0.95, P = 0.02) and cervical cancer (AA vs. AG + GG: OR = 0.56, 95 % CI 0.42-0.75, P < 0.01). Additionally, in subgroup analysis based on ethnicity, significant association was also found between the CTLA-4 +6230G/A polymorphism and cancer risk in the Asian population (AA vs. AG + GG: OR = 0.71, 95 % CI 0.59-0.84, P < 0.01). This meta-analysis indicates that CTLA-4 +6230G/A polymorphism may be associated with a decreased risk of breast cancer and cervical cancer in Chinese population.