The association of CTLA-4 A49G polymorphism with colorectal cancer risk in a Chinese Han population

Cytotoxic T-lymphocyte antigen-4 (CTLA-4) is expressed in T cells and plays an important role in the regulation of T cell. CTLA-4 has long been considered to be associated with various kinds of diseases. With the attempt to examine the association between CTLA-4 A49G polymorphism and colorectal cancer risk in a Chinese Han population, we employed TaqMan assay to genotype the CTLA-4 A49G polymorphism in 311 colorectal cancer cases and 389 cancer-free controls. We found evidence of the association between CTLA-4 A49G polymorphism and colorectal cancer risk (GG vs. AA: OR=2.01, 95% CI=1.29-3.07, P=0.002; GA vs. AA: OR=2.32, 95% CI=1.53-3.57, P=0.001; GA+GG vs. AA: OR=2.16, 95% CI=1.46-3.21, P=0.001). Next, we performed a meta-analysis to comprehensively examine the association between CTLA-4 A49G polymorphism and colorectal cancer risk. We found a significant association between CTLA-4 A49G polymorphism and colorectal cancer risk among Asians, which is consistent with our result. However, we found no evidence for the association between CTLA-4 A49G polymorphism and colorectal cancer risk among Caucasians. In conclusion, we demonstrated that the CTLA-4 A49G polymorphism increased the susceptibility of colorectal cancer in Asian population.