A rapid urinary test for combining PSA and zinc to enhance prostate cancer diagnosis: results from a prospective study

Background: The need for simple, non-invasive biomarkers for prostate cancer (PCa) diagnosis is increasing. Urinary PSA (uPSA) and Zinc (uZinc) are emerging as potential PCa risk indicators. This study aimed to develop a rapid urine test combining uPSA and uZinc, assessing its diagnostic value alone and with Standard of Care (SOC) parameters, including age, serum PSA, DRE, and multiparametric Magnetic Resonance Imaging (mpMRI). Methods: We enrolled 260 men undergoing prostate biopsy. Post-massage urine samples were analyzed using a rapid urine test combining lateral flow immunoassay (uPSA) and colorimetric dipstick assay (uZinc) with confirmatory testing via ELISA and colorimetric in vitro assay. Logistic regression models (SOC, uPSA, uZinc, Urine test [uPSA + uZinc], SOC + Urine test) and mpMRI models were tested. Diagnostic accuracy was evaluated using AUCs from ROC analysis. A decision-making algorithm targeting patients with increased PSA up to 10 ng/mL, negative DRE, and PIRADS ≤ 3 was proposed to assess the number of unnecessary biopsies potentially avoided with the urine test. Results: Among 242 evaluable patients, 146 (59%) had PCa. The rapid Urine test provided intensity scores inversely proportional to biomarker concentration. uPSA strongly correlated with clinical stage, D’Amico risk, and Gleason score, while uZinc showed a weaker trend. The Urine test reached an AUC of 0.769, which improved performance to 0.789 with SOC + Urine test (p = 0.0002). Combining urine markers with mpMRI yielded AUCs of 0.868 (mpMRI+Urine test) and 0.875 (mpMRI+SOC+Urine test; p < 0.0001). The decision-making algorithm integrating urine test demonstrated that 51% of men could safely avoid biopsy, with a 13% detection rate of only low-grade PCas (ISUP < 2) in this group. Conclusions: This uPSA/uZinc urine test is a promising adjunct to current diagnostic pathways, improving accuracy in detecting clinically significant PCa while reducing unnecessary biopsies. Its integration with mpMRI and SOC parameters could refine risk assessment and personalize patient management.