Prognostic impact of microRNA-related gene polymorphisms on survival of patients with colorectal cancer

The polymorphisms in microRNA (miRNA) machinery genes and miRNA-containing genomic regions may play an important role in cancer development and prognosis. Accordingly, the present study analyzed the single nucleotide polymorphisms (SNPs) of miRNA-related genes and their impact on the prognosis for patients with colorectal cancer. Four hundred and twenty-six consecutive patients with surgically treated colorectal adenocarcinoma were enrolled. The genomic DNA was extracted from fresh colorectal tissue and 40 polymorphisms of miRNA-related genes determined using a real-time PCR genotyping assay. In a univariate analysis, the progression-free survival of the patients with the combined mir492 C/G and G/G genotype was significantly worse than that of the patients with the mir492 C/C genotype (rs2289030) (P value = 0.0426), although there was no difference in the overall survival. However, no association was noted between the SNPs of the miRNA-related genes evaluated and survival in a multivariate analysis. None of the 40 miRNA-related gene polymorphisms investigated in this study was found to be an independent prognostic marker for Korean patients with surgically resected colorectal cancer. However, further studies are warranted to clarify the role of miRNA-related gene polymorphisms as a prognostic biomarker for colorectal cancer patients.