LAUSR

Introduction: MicroRNAs (miRNAs) have been linked to advanced prostate cancer; however, their role as circulating biomarkers of prostate cancer (PC) status has yet to be determined. We examined whether circulating miRNAs in plasma could be employed as biomarkers of disease among men treated for PC by radical prostatectomy (RP). Methods: Men with clinically localized PC scheduled for a RP were recruited. Demographics, medical history, clinical information, pre-RP blood, and post-RP blood within 1 year after RP were collected. Pre- and post-RP blood were processed into plasma and the expression of the 16 most statistically significant PC circulating miRNAs in plasma identified from our previous study (miR- 381, 34a, 523, 365, 122, 375, 1255b, 34b, 450b-5p, 639, 885-5p, 1260, 150, 378, 671-3p, 148a) were examined using real-time PCR. Wilcoxon signed ranked test was used to compare the median expression of these miRNAs between pre- and post-RP plasma. Results: There were 29 men, aged 43 to 77 years, included. Majority were white men (79.3%). The median preoperative serum PSA was 6.3 ng/mL. Majority had a pathologic Gleason score of 7 (3+4) (56%) and a pathologic tumor stage of T3 (60.7%). There was no statistically significant difference in miRNA expression between pre- and post-RP plasma. Conclusion: No difference in miRNA expression before and immediately after RP was observed, possibly due to the lack of impact of tumor removal on miRNA expression and the timing of plasma collections. Future studies that examine post-RP plasma miRNA expression over time with PC recurrence are warranted. Citation Format: Alicia C. McDonald, Jay D. Raman, Jing Shen, Jason Liao, Manish Vira. Comparison of circulating microRNAs in plasma before and after radical prostatectomy among men treated for prostate cancer [abstract]. In: Proceedings of the AACR Special Conference: Prostate Cancer: Advances in Basic, Translational, and Clinical Research; 2017 Dec 2-5; Orlando, Florida. Philadelphia (PA): AACR; Cancer Res 2018;78(16 Suppl):Abstract nr A002.