The prognostic value of circulating miRNAs in patients with localized/locally advanced prostate cancer after radical prostatectomy and radiotherapy.

Abstract

184 Background: The outcome after curative intended management of local prostate cancer (PC) is promising. However, there is still a risk of biochemical relapse (BR) after either radical prostatectomy (RP) or radiotherapy (RT). MicroRNAs (miRNAs) have showed encouraging results as alternative biomarkers in different settings of PCa. The aim of this study was to investigate the prognostic value of circulating miRNAs after management of local PCa. Methods: In total 107 newly diagnosed patients with local or locally advanced PCa were included in the study. The cohort was divided into an interventional group with 59 patients (RP (39 patients) or RT (20 patients)) and an observational group with 48 patients (active surveillance (AS)). Both baseline samples at time of diagnosis and follow-up samples six months after treatment were collected. The relative expression of four miRNAs (miRNA-21, -93, -125b, and miRNA-221) was assessed in plasma using real-time polymerase chain reaction. Results: In the interventional cohort, the decrease in miRNA-125b after RT was significantly associated with a longer time to biochemical recurrence (BR) (HR= 0.17, p=0.03), and a higher level of miRNA-125b at baseline samples showed a tendency to higher risk for BR in the same population (HR= 2.82, p=0.09). On the other hand, lower levels of miRNA-221 at both baseline and follow-up samples tended to be associated with lower risk of BR in patients managed by RT (HR=0.14, p=0.07, and HR=0.13, p=0.07, respectively). None of these four miRNAs was associated with a significant risk of progression in patients managed by AS. Conclusions: Both baseline and the dynamics of miRNA-125b was informative as to the risk of BR in patients with PCa treated by RP. Validation in independent cohorts is called for.