We investigated whether four common microRNA polymorphisms (miR-146aC>G [rs2910164], miR-149T>C
[rs2292832], miR-196a2T>C [rs11614913], and miR-499A>G [rs3746444]) are associated with the susceptibility and
prognosis of gastric cancer in the Korean population. The four microRNA single-nucleotide polymorphisms (SNPs)
were identified in a case–control study (461 patients; 447 controls) by polymerase chain reaction–restriction fragment
length polymorphism (PCR–RFLP) analysis in the Korean population. When patients were stratified into diffuse and
intestinal-type gastric cancer groups, subjects with the miR-499AG and AG þ GG genotypes had reduced adjusted
odds ratios (AORs) for diffuse-type gastric cancer (AOR ¼ 0.54 with 95% confidence interval [CI] ¼ 0.31–0.97;
AOR ¼ 0.57 with 95% CI ¼ 0.33–0.97). In the stratified analyses for gastric cancer risk, the miR-146aGG and
CG þ GG genotypes were associated with increased risk of gastric cancers among the non-smokers, whereas the
miR-149TC and TC þ CC genotypes showed lower risk of gastric cancer in males. The miR-196a2CC genotype was
associated with elevated gastric cancer risk among females. For gastric cancer prognosis, intestinal-type gastric cancer
patients with miR-146aCG þ GG genotypes had significantly higher survival rates (log-rank P ¼ 0.030) than patients
with the CC genotype, and patients with the miR-499AA genotype had significantly increased survival rates compared
to patients with the AG þ GG genotypes (log-rank P ¼ 0.013). When miR-146aCG þ GG and miR-499AA genotypes
were combined, the survival rate of intestinal-type gastric cancer patients was elevated (log-rank P < 0.001). No
association was found between gastric or diffuse-type cancer prognosis and other miRNAs. Our data demonstrate
that specific miRNA SNPs are associated with gastric cancer susceptibility (miR-499A>G) and prognosis (miR-
146aC>G and miR-499A>G) in the Korean population depending on gastric cancer type