To compare the rate of diagnosing clinically significant prostate cancer (csPCa) in men with elevated PSA stratified by baseline IsoPSA Index, thus assessing IsoPSA's intermediate-term predictive ability for csPCa.
Single-center retrospective review of consecutive patients (n=1578) who underwent IsoPSA testing from November 2016-August 2022. Data dichotomized into patients with low(≤6) and high IsoPSA Indices (>6). Most recent subsequent IsoPSA and PSA tests, prostate biopsy, and MRI collected. Time-to-event Kaplan-Meier estimates generated for the risk of csPCa stratified by baseline IsoPSA Index.
Among 541 patients with initial low IsoPSA Indices (≤6), 23 (4.3%) were diagnosed with csPCa on a subsequent biopsy. Also, among these 541 patients, 204 had an MRI, of which 48/204 (23.5%) showed suspicious lesions(PIRADS≥4). Among 1037 patients with initial high IsoPSA Indices, 366 (35.3%) were diagnosed with csPCa on a subsequent biopsy. Also, among these 1037 patients, 712 had an MRI, of which 342/712 (48.0%) showed suspicious lesions (PIRADS≥4). After 12, 24, and 30 months, respectively, the risk of developing csPCa was 0.4% (95% CI 0.1%-1.6%), 2.5% (1.4%-4.4%), and 6.3% (4%-9.6%) in patients with low IsoPSA Indices, compared to 5.9% (4.6%-7.6%), 31.7% (28.3%-35.4%), and 49.5% (45.3%-53.9%) in patients with high IsoPSA Indices. Limitations include the retrospective review of prospectively collected data and unknown true csPCa rates as not all patients were biopsied.
The risk of developing csPCa was smaller in patients with initial low vs high IsoPSA Indices over the ensuing 30 months, which supports using IsoPSA to safely avoid follow-up testing.
Urology. 2025 Jan 15 [Epub ahead of print]
Nour Abdallah, Rebecca A Campbell, Tarik Benidir, Andrew Wood, Zaeem Lone, Ao Zhang, Onuralp Ergun, Caleb Curry, Patrick Michael, Ross Liao, Jaya Sai Chavali, Alberto Pieretti, Jesse McKenney, Andrei Purysko, Samuel Haywood, Zeyad Schwen, Ruben Olivares, Jihad Kaouk, Robert Abouassaly, Eric A Klein, Christopher J Weight
Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, Ohio, United States of America. Electronic address: ., Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, Ohio, United States of America., Cleveland Clinic Lerner College of Medicine, Cleveland, Ohio, United States of America., Department of Urology, University of Minnesota, Minneapolis, Minnesota, United States of America., Department of Urology, Cleveland Clinic Florida, Weston, Florida, United States of America., Department of Pathology, Cleveland Clinic, Cleveland, Ohio, United States of America., Abdominal Imaging Section and Nuclear Radiology Department, Imaging Institute, Cleveland Clinic, Cleveland, Ohio, United States of America.