MiR-146a rs2910164 polymorphism increases risk of gastric cancer:A meta-analysis

AIM:To systematically evaluate the association between the miR-146 a rs2910164 polymorphism and susceptibility to gastric cancer.METHODS:A comprehensive electronic search was conducted for articles published up until January 27,2014 in Medline(PubMed),Excerpta Medica Database(Embase),the Cochrane Library and Google Scholar.Only case-control studies published in English that evaluated the association between the miR-146 a rs2910164 polymorphism and susceptibility to gastric cancer were included.Furthermore,only studies with sufficient data allowing for calculation of odds ratio(OR) and corresponding 95% confidence interval(CI) were included.These values were used in the quantitative synthesis to assess the strength of the association between the miR-146 a rs2910164 polymorphism and risk of gastric cancer.RESULTS:The database search identified 1002 eligible studies,of which seven(comprising 4112 cases and 5811 controls) were included for the meta-analysis.The results indicate that miR-146 a rs2910164 polymorphism is more likely to be associated with gastric cancer risk.In the overall analysis,a significantly increased cancer risk was found in the heterozygote(GG vs GC) comparison(OR = 1.14,95%CI:1.03-1.27; P = 0.01 for pooled OR).In the ethnicity subgroup analysis,a similar result was found among Caucasians(OR = 1.36,95%CI:1.01-1.85; P = 0.04 for pooled OR).In the stratified analysis by quality of studies,a significantly increased cancer risk was found in the heterozygote comparison among high quality studies(OR = 1.12,95%CI:1.01-1.26; P = 0.04 for pooled OR).When stratified on the basis of sample size,a significantly increased cancer risk was found among small sample size subgroups for the allelic(G vs C:OR = 1.16,95%CI:1.03-1.30; P = 0.01),homozygote(GG vs CC:OR = 1.33,95%CI:1.03-1.73; P = 0.03) and recessive model(GG vs GC + CC:OR = 0.05,95%CI:0.00-0.10; P = 0.03) comparisons.CONCLUSION:The miR-146 a rs2910164 polymorphism is associated with increased gastric cancer risk,particularly evident in high quality studies with small sample sized Caucasian populations.