miR-194 as a predictor for adenoma recurrence in patients with advanced colorectal adenoma after polypectomy

microRNAs (miRNA) are promising predictors in colorectal cancer (CRC). We investigated whether miRNAs could predict adenoma recurrence in patients with advanced colorectal adenoma (ACRA) after polypectomy. miRNA expression profiling was performed by miRNA microarray to identify recurrence-related miRNAs. Candidate miRNAs extracted from formalin-fixed paraffin-embedded blocks of patients with ACRA were measured using real-time PCR. Logistic regression analysis was conducted to investigate whether validated miRNA expression profiles were independent from other known adenoma recurrence risk factors. The prognostic values of six miRNAs and three independent risk factors were assessed by the area under the receiver operating characteristic (ROC) curve analysis. The expressions of six candidate miRNAs were significantly decreased from levels in normal colorectal tissue compared with ARCA with adenoma recurrence (RACRA) in this retrospective cohort. However, only miRNA (miR)-194 emerged as a practical predictor. The sensitivity and specificity of miR-194 as a predictor were 71.0% and 78.0%, respectively, at a cutoff value of 0.1311 in the retrospective cohort. Sensitivity and specificity were 76.1% and 77.2%, respectively, in the prospective cohort using the same cutoff value. Low expression levels of miR-194, adenoma size ≥2 cm, and ≥3 adenomas were independent risk factors for adenoma recurrence. Moreover, low expression of miR-194 was a better predictor of adenoma recurrence than the adenoma size and numbers according to ROC curve analysis. miR-194 may be an independent predictor for adenoma recurrence in patients with ACRA after polypectomy.