Combining PHI and miRNAs as Biomarkers in Prostate Cancer Diagnosis and Prognosis

Background: Prostate cancer (PC) is considered the fifth most common cancer causing death worldwide. Many studies have pointed to dysregulated microRNA (miRNA) expression in PC and their use in early detection and follow-up of the disease. In addition, the Prostate Health Index (PHI) is the FDA-approved blood test joining total, free, and -2proPSA having greater specificity than free and total PSA for assessment of PC. Methods: In this study, we evaluated the plasma levels of miR-21 and miR-221 expression using quantitative real-time polymerase chain reaction (qRT-PCR) among 100 prostate cancer patients (50 localized and 50 metastatic cases) and 50 benign prostatic hyperplasia patients in comparison to 50 normal control subjects, as well as assessed its diagnostic and prognostic value and its correlation with the Prostate Health Index (PHI). Results: To our knowledge, we are the first study to join PHI with miRNAs in assessing PC diagnosis and prognosis. Our results showed that adding miR-21 to PHI for detecting patients with LPC, increased the sensitivity to 95.5% at a specificity 100% (p < 0.0001). Additionally, combining miR-221 and PHI for differentiating patients with MPC, increased the sensitivity to 96.4% at a specificity 100% (p < 0.0001). Conclusions: The potentials of circulating miR-21, miR-221, and PHI serum level as biomarkers for PC have been established not only as diagnostic factors but also as prognostic markers.