The TLR9 Gene Polymorphisms and the Risk of Cancer: Evidence from a Meta-Analysis

BACKGROUND Growing studies have revealed the association between polymorphisms in the Toll-like receptor 9 (TLR9) and susceptibility to cancer, however, the results remained inconsistent. METHODOLOGY/PRINCIPAL FINDINGS To assess the effect of three selected SNPs (rs352140, rs5743836 and rs187084) in TLR9 on cancer, we performed a meta-analysis based on 11 case-control studies, including a total of 6,585 cancer cases and 7,506 controls. Summary odds ratios (OR) and corresponding 95% confidence intervals (CIs) for polymorphisms in TLR9 and cancer risk were estimated. Our meta-analysis indicated that rs352140 was associated with an increased cancer risk, especially in Caucasian. However, no significantly increased cancer risk was detected to be associated with rs187084 and rs5743836 either the overall or subgroup estimation. CONCLUSIONS These meta-analysis results indicate that polymorphisms in TLR9 may play a role in cancer development.