The constant hope and conversation of late has surrounded what is referred to as a liquid biopsy. The hope and goal is to no longer need to have an invasive needle biopsy to diagnose and stage prostate cancer. Biopsies are not accurate because there are too many false negatives, they only evaluate the actual tissue sampled and do not take into consideration the un-sampled tissue (which can have a different type or stage of cancer present). They also are painful and worse expose men to the possibility of infections, some of which can be life threatening.
We dream of finding an alternative to these invasive biopsies, either by performing an analysis of a man’s urine or blood (aka a liquid biopsy), eliminating the need for a needle biopsy. A good and validated liquid biopsy might prove to be more accurate and eliminate the need for subjecting a man to a biopsy that is painful and puts him at risk for an infection.
Two posters at ASCO GU presented clinical data that supports Exosome Diagnostics Inc. plan to develop a test for monitoring at-risk men. Preliminary results from a prospective validation study showed that their urine test accurately predicted a man’s Gleason Score, pathologic stage, and tumor volume in prostatectomy specimens.
The test, currently referred to as Prostate (IntelliScore), is a completely non-invasive urine-based liquid biopsy for prostate cancer, that seems to have the unique ability to accurately identify high-grade prostate cancer (HGPCA) both at the time of biopsy and at surgery. These data demonstrate the potential for this first-in-class exosomal RNA (exoRNA)-based assay to be utilized throughout the care continuum, including prior to initial biopsy, as well as for sequential monitoring of disease progression in men enrolled in active surveillance.
“The current diagnostic landscape for prostate cancer is imprecise, setting off a cascade of events that starts with unnecessary and inaccurate biopsies, and leads to over-diagnosis and over-treatment of the disease with radical treatment choices including prostatectomies,” said co-author James A. Eastham, M.D., Chief of Urology, Memorial Sloan Kettering Cancer Center. “This assay’s ability to give urologists a more precise, genetically informed understanding of a man’s risk for aggressive disease via a simple urine sample, without the need for an invasive prostate tissue biopsy could help prevent that cascade. In the coming years, I believe we’re going to see the continual and much-needed transformation of the diagnostic and treatment pathway of prostate cancer.”
The test also seems to be valid for both Caucasian men and men of African American descent.
This test, as it continues to be validated bears our careful scrutiny.