Expression of hsv1-miR-H18 and hsv2-miR-H9 as a field defect marker for detecting prostate cancer

BACKGROUND: Prostate-specific antigen (PSA) is a marker of prostate cancer (PCa), although its efficacy as a diagnostic marker remains controversial. A high false-positive rate leads to repeat biopsy in approximately 70% of patients, which may not be necessary. Epigenetic biomarkers of field cancerization have been investigated widely as promising tools for the diagnosis of patients with suspected tumors. In the current study, we examined the diagnostic value of two microRNA (miRNA) candidates, hsv1-miR-H18 and hsv2-miR-H9, using formalin-fixed paraffin-embedded (FFPE) tissues from patients with PCa or benign prostate hyperplasia (BPH) (as controls) to determine the usefulness of these markers for detecting the presence of cancer. METHODS: Expression of hsv1-miR-H18 and hsv2-miR-H9 in 201 FFPE tissues, including 52 primary tumors, 73 surrounding noncancerous tissues, and 90 BPH nontumor controls was examined by real-time PCR. RESULTS: Expression of hsv1-miR-H18 and hsv2-miR-H9 was significantly higher in primary tumors from PCa patients than in BPH controls (P < 0.0001). In patients within the PSA gray zone, the two viral miRNAs could distinguish PCa from controls with appropriate sensitivity and specificity. Expression of the two miRNAs did not differ between primary tumors and noncancerous surrounding tissues. CONCLUSIONS: The viral miRNAs hsv1-miR-H18 and hsv2-miR-H9 may be associated with field cancerization of PCa and could be promising supplemental biomarkers to the PSA assay to decrease the rate of unnecessary biopsy, particularly in patients within the PSA gray zone.