Prostate cancer (PCa) is the second leading cause of cancer death among men in the United States, with an anticipated 233,000 new cases and nearly 29,480 deaths in 2014. The definitive diagnostic for PCa is the prostate needle biopsy, typically recommended for men with elevated serum PSA levels and/or a suspicious digital rectal exam (DRE) with added indication from family history, age and race. The majority of prostate cancers remain indolent, infrequently resulting in death. Thus, there is a major risk for detecting cancers that are clinically insignificant and do not require treatment. Unfortunately, due to the low positive predictive value (PPV) of PSA and the high prevalence of low risk PCa, approximately 70% to 80% of men will undergo an unnecessary biopsy. There is a critical need to reduce initial prostate biopsies (PB) in the PSA ‘gray zone’ of 2-10 ng/mL. Non-invasive screening tools that add predictive value for identifying high-grade, Gleason score (GS) ≥7 should impact the current diagnostic paradigm. We have developed standardized processes to isolate exosomal RNA (exoRNA) from first-catch urine specimens and sought to identify a gene signature that reliably differentiates GS7+ from GS6 and benign disease.
March 12, 2018