Diagnostic significance of miR-21, miR-141, miR-18a and miR-221 as novel biomarkers in prostate cancer among Egyptian patients.

Prostate cancer (PC) is considered as the fifth cause of cancer deaths worldwide. The exact etiopathogenesis is unclear; however, genetic predisposition, hormonal influencers, lifestyle and environmental factors act as major contributors. It has been found that several miRNAs may play a crucial role in cancer initiation and progression. Here, in this study, we evaluated the peripheral blood levels of miR-21, miR-141, miR-221 and miR-18a expression among 80 prostate cancer patients (50 localised and 30 metastatic) and 30 benign prostatic hyperplasia patients compared to 50 normal control subjects, using RT-PCR. Our results of analysis of miR-21, miR-141, miR-18a and miR-221 in the plasma of PC patients showed that miR-18a is a powerful discriminator of PC patients from healthy controls as it had the highest AUC (0.966; 95% CI, 0.937-1.000), while miR-221 provided better differentiation of metastatic from localised PC (sensitivity was 92.9% at 100% specificity), and when we combine miR-18a and miR-221 for differentiating patients with MPC, it will increase the sensitivity to 96.4% at a specificity of 100% (AUC, 0.997; 95% CI, 0.988-1.0) (p < .000). This current study recommends that analysis of these miRNAs might have clinical value in enhancing PSA testing.