Introduction: The ExoDx Prostate (EPI) test has been well validated for prostate cancer (PC) biopsy decisions. Here we investigate combining MRI with EPI from patients pre-staged by MRI prior to biopsy (Bx).
Methods: Pre-Bx urine was collected from men with no history of PC, aged =50 years, with a PSA 2-10 ng/mL, who were previously staged with MRI. Bx was performed when PIRADs >=3 at a single site (LMU). A subset of men had radical prostatectomy (RP). For analysis of MRI and biomarker models, the RP result when available, was utilized to enable more accurate tissue status.
Results: Of the 170 patient samples collected, MRI status was available for 168 patients, 160 had an EPI result, 143 underwent Bx and 40 men proceeded to RP. PIRADS scores encompassed PIRADS 1/2 in 24 (14%) patients, PIRADS 3 in 32 (19%), and PIRADS 4/5 in 112 (67%). Bx pathology indicated 35.2% >=GG2 and 72.5% in the RP group. Both higher Gleason Grade groups (GG) and higher EPI Scores increased with higher PIRADS Score as shown in Figure 1. A new model was generated by combining the EPI score and MRI result (training (N=116) and test (N=29), resulting in an increased AUC (0.88) compared to either EPI (0.68) or MRI alone (0.75).
Conclusions: The combination of MRI and EPI is better than either alone and suggests that this combined approach is more clinically useful when conducted before the Bx decision.
Source of Funding: Study was funded by Exosome Diagnostics, Waltham, MA, USA
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