Abstract
BACKGROUND: Associations between cytotoxic T lymphocyte antigen-4 (CTLA-4) +49A/G polymorphism and cancer risk are inconclusive. We performed this meta-analysis to derive a more precise estimation of the relationship. METHODS: A comprehensive literature search was performed using electronic databases. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association. RESULTS: A total of 16,358 cases and 19,737 controls from 46 studies were included. Overall, significant association between CTLA-4 +49A/G polymorphism and cancer risk was observed in all genetic models (G vs. A: OR=0.88, 95%CI=0.83-0.93, PH=0.000; GA vs. AA: OR=0.87, 95%CI=0.79-0.97, PH=0.000; GG vs. AA: OR=0.75, 95%CI= 0.65-0.86, PH=0.000; GG vs. GA+AA: OR=0.84, 95%CI=0.79-0.91, PH=0.001; GG+GA vs. AA: OR=0.83, 95%CI=0.74-0.92, PH=0.000). Stratified analysis by cancer type revealed that the CTLA-4+49A/G polymorphism is associated with the decreased risk of cervical cancer, breast cancer, lung cancer, HCC. Further subgroup analysis by ethnicity indicated that there was a statistically decreased cancer risk in Asian population. CONCLUSION: This meta-analysis suggests that CTLA-4+49A/G polymorphism is associated with cancer risk, especially in Asian population.