['Emerging evidence suggested that microRNAs (miRNAs) play a causal role in cancer tumorigenesis. Aberrant expression of miRNA (miR)-139-5p has been observed in various types of cancers. The present study evaluated the relationship between miR-139-5p expression levels and prostate cancer (PCa), to assess the feasibility of using peripheral blood miR-139-5p as a potential non-invasive biomarker for PCa.', 'Total RNA was extracted from peripheral whole blood samples from 45 PCa patients, 45 benign prostatic hyperplasia (BPH) patients and 50 healthy controls (HC). The expression of miR-139-5p was assessed by reverse transcription quantitative polymerase chain reaction.', 'MiR-139-5p in peripheral blood was significantly higher in PCa patients than in patients with BPH and HC individuals (P<0.001). Higher miR-139-5p expression was observed to be associated with certain clinicopathological parameters, including PSA>20ng/ml (P<0.05), pathological tumor stage 3/4 (P<0.05) and Gleason score >7 (P<0.01). A receiver operating characteristic (ROC) curve analysis revealed that miR-139-5p distinguished PCa patients from BPH patients [area under the curve (AUC), 0.936; 95% CI, 0.878-0.993; P<0.001].'] Is miR-139-5p Increased in the Peripheral Blood of Patients with Prostate Cancer?