MicroRNA profiling in clear cell renal cell carcinoma tissues potentially links tumorigenesis and recurrence with obesity

Background: Twenty to 40% localised RCC patients may experience recurrence after curative surgery. Limited miRNA predictors have been identified for ccRCC recurrence. Methods: Through a multi-phase study design, we analysed miRNAs in tissues obtained from 203 ccRCC patients. Paired t -test was used for tumour–normal comparisons and Cox regression model was performed to compute hazard ratios (HRs) and corresponding 95% CIs. Results: A 17-miRNA signature was identified that can concordantly classify >95% of tumour/adjacent normal samples. Significant enrichment was found as 6 out of 17 miRNAs were associated with obesity (binomial probability=0.001). Decreased levels of miR-204-5p and miR-139-5p were each associated with an approximately three-fold increased risk of recurrence ( P 70.3 months). Expressions of miR-204-5p were also associated with body mass index ( β =5.64, P