Association between microRNA-27a rs895819 polymorphism and risk of colorectal cancer: A meta-analysis

Colorectal cancer (CRC) is the most common malignancy in the human digestive system. Previous results regarding the association between microRNA-27a rs895819 polymorphisms and CRC risk are controversial. We therefore performed a meta-analysis of seven studies totaling 2230 cases and 2775 controls to systematically evaluate this association. Summary odds ratios (ORs) and 95% confidence intervals (Cls) were obtained using a fixed-effects model. A moderate evidence for the association between mir-27a polymorphism and CRC risk was found under multiple genetic models (dominant model: OR = 1.15, 95% CI: 1.02-1.29, p = 0.02; recessive model: OR = 1.49, 95% CI: 1.27-1.76, p < 0.001; homozygote model: OR = 1.53, 95% CI: 1.28-1.83, p < 0.001; allele model: OR = 1.21, 95% CI: 1.11-1.31, p < 0.001). Subgroup analysis showed a significant association between mir-27a rs895819 polymorphism and CRC risk among Chinese populations. On the contrary, we found no evidence of association among Caucasian populations due to small samples (p > 0.05). In conclusion, this meta-analysis suggested that rs895819 polymorphism in mir-27a may be a potential genetic risk factor for CRC, particularly in Chinese populations.