Published online Nov 7, 2014. doi: 10.3748/wjg.v20.i41.15440
Revised: May 22, 2014
Accepted: July 11, 2014
Published online: November 7, 2014
Processing time: 242 Days and 9.9 Hours
AIM: To systematically evaluate the association between the miR-146a 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-146a 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-146a 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-146a 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-146a rs2910164 polymorphism is associated with increased gastric cancer risk, particularly evident in high quality studies with small sample sized Caucasian populations.
Core tip: Recent attention has been focused on the role of miR-146a gene variants in the etiology of several cancers. An increasing number of studies have suggested that the single nucleotide polymorphism rs2910164 in miR-146a is associated with gastric cancer risk. However, previous meta-analyses have failed to find an association. To better understand this association, an up-to-date comprehensive meta-analysis was conducted, which indicates that the miR-146a rs2910164 polymorphism is indeed more likely to be associated with gastric cancer risk.