Salivary and serum microRNAs as noninvasive biomarkers for distinguishing prostate cancer from benign prostatic hyperplasia.

OBJECTIVES

Accurate differentiation of prostate cancer (PCa) from benign prostatic hyperplasia (BPH) is challenging due to prostate-specific antigen's (PSA's) limited specificity. Circulating and salivary microRNAs (miRNAs) have emerged as promising noninvasive biomarkers. This study aimed to evaluate the diagnostic potential of selected miRNAs in serum and saliva, individually and combined with PSA, for distinguishing PCa from BPH.

METHODS

In this case-control study, 100 male participants (50 with PCa, 50 with BPH) provided paired serum and saliva samples. Ten candidate miRNAs (miR-182, miR-96, miR-18a, miR-193a-5p, miR-744, miR-573, miR-210, miR-323, miR-101, miR-203) were quantified by real-time quantitative polymerase chain reaction, and PSA levels were measured by enzyme-linked immunosorbent assay. Diagnostic accuracy was assessed via receiver operating characteristic analysis, and correlations between serum and salivary markers were evaluated.

RESULTS

Compared with the BPH group, 8 miRNAs (miR-182, miR-96, miR-18a, miR-193a-5p, miR-744, miR-573, miR-210, miR-323) were significantly upregulated in PCa, whereas miR-101 and miR-203 were downregulated. Salivary miRNA levels strongly mirrored serum profiles (r = 0.70-0.91, P < .001). The ROC analysis identified miR-182 and miR-96 as the most discriminatory markers (area under the curve [AUC] > 0.82). Combining PSA with these miRNAs improved diagnostic accuracy (serum PSA + miR-182/96: AUC 0.92/0.90, 91%/89% sensitivity, 88.6%/86.2% specificity; saliva: AUC 0.88/0.86, 88%/86% sensitivity, 84%/82% specificity).

CONCLUSIONS

Selected miRNAs, particularly miR-182 and miR-96, reliably differentiate PCa from BPH in both serum and saliva. Integration with PSA further enhances diagnostic performance, and salivary profiling represents a practical, noninvasive approach for early molecular screening.