We found that CT (miR-196a2, C>T rs11614913) was a risk factor for renal cell carcinoma (CT vs. CC: OR = 1.72, 95%CI = 1.05-2.80, <i>P</i> = 0.03, <i>I</i><sup>2</sup> = 66%), especially in Asian population (CT vs. CC: OR = 1.17, 95%CI = 1.04-1.32, <i>P</i> < 0.01, <i>I</i><sup>2</sup> = 0%). miR-146a G>C rs2910164 was a protective factor of urological cancers (C vs. G: OR = 0.87, 95%CI = 0.81-0.93, <i>P</i> < 0.01, <i>I</i><sup>2</sup> = 0%), especially for bladder cancer. miR-499 A>G rs3746444 was correlated with an increased risk of urological cancers, specifically in Asian population.
Our results suggested hsa-mir-196a2 rs11614913 C/T is associated with a significantly decreased risk of bladder cancer and hsa-mir-146a rs2910164 GG genotype is associated with clinical stage and metastasis in bladder cancer.
Even though there was no association between the individuals carrying the variant genotypes of the three miRNA studied and bladder cancer risk, marginal significance of heterozygousity in rs11614913 suggested further characterization of miRNA SNPs in a large cohort of varied ethnicity.