UPJ Insight: IsoPSA Reduces Provider Recommendations for Biopsy and Magnetic Resonance Imaging in Men with Total Prostate Specific Antigen 4 ng/ml: A Real-World Observational Clinical Utility Study

By: Jason M. Scovell, MD, PhD; Daniel Hettel, MD; Robert Abouassaly, MD; Nima Almassi, MD; Ryan Berglund; Todd Breaux, MD; Christopher Weight, MD; Wahib Isac, MD; Anna Zampini, MD; Elizabeth Stark, PA-C; Robert Rochelle, BS, MBA; Aimee Kestranek, BS; Mark Stovsky, MD, MBA; Eric A. Klein, MD | Posted on: 01 Apr 2022

Scovell JM, Hettel D, Abouassaly R et al: IsoPSA® reduces provider recommendations for biopsy and magnetic resonance imaging in men with total prostate specific antigen ≥4 ng/ml: a real-world observational clinical utility study. Urol Pract 2021; https://doi.org/10.1097/UPJ.0000000000000291.

Study Need and Importance

IsoPSA^® is a novel, structure-based test directly linked to tumor biology. IsoPSA has been validated in a large, prospective, multicenter study to have superior performance compared to prostate specific antigen (PSA) and percent free PSA, and demonstrated to have the ability to reduce costs. IsoPSA is intended for use in men age ≥50 years undergoing evaluation for total PSA levels ≥4 ng/ml and <100 ng/ml. It is clear that IsoPSA is an effective biological marker. Would IsoPSA be readily adopted and acted on by a broad group of practitioners assessing men undergoing evaluation for elevated PSA and concern for prostate cancer? Here we evaluated test utilization and impact on patient management recommendations in a real-world clinical setting.

“IsoPSA has been validated in a large, prospective, multicenter study to have superior performance compared to prostate specific antigen (PSA) and percent free PSA, and demonstrated to have the ability to reduce costs.”

Table. Summary of biopsies recommended before and after IsoPSA results by patient biopsy history

Cohort	No.	No. Biopsies Recommended before IsoPSA	No. Biopsies Recommended after IsoPSA	% Reduction in Biopsies Recommended
All subjects	734	638	284	55.5
Biopsy naïve	408	370	173	53.2
Prior neg biopsy	326	268	113	57.8

What We Found

A total of 38 providers practicing in a range of settings, including community-based family health centers, hospital-based medical office facilities and the main campus academic practice location within the Cleveland Clinic system in Northeast Ohio, enrolled 900 patients. Providers used IsoPSA results to affirm or modify their recommendations for prostate biopsy. There was a 55% net reduction in biopsies recommended and a 9% net reduction in magnetic resonance imaging scans recommended. Final provider recommendations for biopsy aligned closely with IsoPSA results (87% biopsy when recommended pre-test, 92% against biopsy when not recommended pre-test). Biopsy reduction rates were similar across both biopsy-naïve (53%) and prior negative biopsy patients (58%; see table). Provider behavioral changes were similar across practitioner type, suggesting that IsoPSA utilization is practical among providers with different educational backgrounds.

Limitations

There are no long-term outcome data associated with this study, which was outside the scope of the assessed primary end point.

“Final provider recommendations for biopsy aligned closely with IsoPSA results (87% biopsy when recommended pre-test, 92% against biopsy when not recommended pre-test).”

Interpretation for Patient Care

IsoPSA is readily adopted across a variety of practitioner types and practice settings. Clinicians are comfortable interpreting and acting on these results. This led to a 55% net reduction in prostate biopsies for men undergoing evaluation for elevated PSA.