Urinary microRNAs expression in prostate cancer diagnosis: a systematic review.

PURPOSE: Circulating microRNAs (miRNAs) have been shown to have the potential as noninvasive diagnosis biomarkers in several types of cancers, including prostate cancer (PCa). Urine-based miRNA biomarkers have been researched as an alternative tool in PCa diagnosis. However, few studies have performed miRNA detection in urine samples from PCa patients, as well as low numbers of miRNAs have been assayed, and there is a lack of standard strategies for validation. In this context, we conducted an in-depth literature review focusing on miRNAs isolated from urine samples that may contribute to the diagnosis of PCa. METHODS: A systematic review was performed searching the PubMed, Lilacs and Cochrane Library databases for articles focused on the value of significantly deregulated miRNAs as biomarkers in PCa patients. RESULTS: Only 18 primary manuscripts were included in this review, according to the search criteria. Our results suggest that miR-21-5p, miR-141-3p, miR-375 and miR-574-3p should be considered as potential urinary biomarkers for the diagnosis of PCa. CONCLUSION: These results suggested that large-scale prospective studies are still needed to validate our findings, using standardized protocols for analysis.