The ExoDx Prostate Intelliscore urine exosome assay is a noninvasive, urinary 3-gene expression assay that discriminates high-grade (≥GS7) from low-grade (GS6) cancer and benign disease. This according to an assay developed in a training cohort of 499 patients with PSA level from 2 to 20 ng/mL and validated in 1,064 patients. Researchers found:

• In a targeted population within the training cohort, the urine exosome gene expression assay plus standard of care (SOC) was associated with improved discrimination between GS7 or greater and GS6 and benign disease: area under the curve (AUC)=0.77 vs SOC AUC=0.66.

• In the targeted population within the validation cohort, the urine exosome gene expression assay plus SOC AUC=0.73 was superior to SOC AUC=0.63.

• Using a predefined cut point, 27% of biopsies would have been avoided, missing only 5% of patients with dominant pattern 4 high-risk GS7 disease.

Citation: McKiernan J, Donovan MJ, O’Neill V, et al. A novel urine exosome gene expression assay to predict high-grade prostate cancer at initial biopsy. [Published online ahead of print March 31, 2016]. JAMA Oncol. doi:10.1001/jamaoncol.2016.0097.