Pre-diagnosis urine exosomal RNA (ExoDx EPI score) is associated with post-prostatectomy pathology outcome

Purpose ExoDx Prostate IntelliScore (EPI) is a non-invasive urine exosome RNA-based test for risk assessment of high-grade prostate cancer. We evaluated the association of pre-biopsy test results with post-radical prostatectomy (RP) outcomes to understand the potential utility of EPI to inform invasive treatment vs active surveillance (AS) decisions. Methods Urine samples were collected from 2066 men scheduled for initial biopsy with PSA between 2 and 10 ng/mL, no history of prostate cancer, and >= 50 years across multiple clinical studies. 310 men proceeded to RP, of which 111 patients had Gleason group grade 1 (GG1) at biopsy and would have been potential candidates for AS. We compared pre-biopsy urine scores with ERSPC and PCPT multivariate risk calculator scores for men with GG1 at biopsy to post-RP pathology. Results Urine EPI scores were significantly lower in men with GG1 at biopsy than in men with > GG1 (p = 0.04), while there were no differences in multivariate risk scores used in standard clinical practice (p > 0.05). Further, EPI scores were significantly lower in men with GG1 at biopsy who remained GG1 post-RP compared to men upgraded to >= GG3 post-RP (p < 0.001). In contrast, none of the multiparametric risk calculators showed significant differences (p > 0.05). Men with GG1 at biopsy and EPI score < 15.6 had zero rate of upgrading to >= GG3 post-RP compared to 16.0% for EPI scores >= 15.6. Conclusions The EPI urine biomarker outperformed the multivariate risk calculators in a homogenous risk group of pre-biopsy men. The EPI score was associated with low-risk pathology post-RP, with potential implications on informing AS decisions.