Aims: The presence of single nucleotide polymorphisms contributes to genetic diversity, and some are associated with cancer progression. Recent studies concerning the relationship between polymorphisms in miR-146a and the risk of papillary thyroid carcinoma (PTC) have produced conflicting results. Here, a meta-analysis of previous studies was performed to evaluate this relationship. Materials and Methods: Electronic databases, including PubMed, China National Knowledge Infrastructure, Cochrane Library, Embase, and Web of Science, were searched for studies concerning miR-146a and PTC published between January 1, 2000 and January 1, 2018. Fixed/random-effects models were used to calculate the pooled odds ratios (ORs) estimated in each study according to the level of heterogeneity. Results: Eight studies involving 3993 cases and 9919 controls were assessed. Pooled results showed no association between the miR-146a rs2910164 polymorphism and PTC (OR = 1.001, 95% confidence interval [CI] 0.893-1.121). Subgroup analysis showed that the GG/GC genotype did not significantly increase PTC risk versus CC among Asians (OR = 0.939; 95% CI 0.828-1.066). Similarly, the combination of the GG and GC genotypes did not increase the risk of PTC for Caucasians (OR = 1.571, 95% CI 0.949-2.601). Conclusions: The results of our meta-analysis indicated that the miR-146a rs2910164 variant genotype has no effect on susceptibility to PTC.
Keywords: meta-analysis; miR-146a; papillary thyroid carcinoma; polymorphism; susceptibility.