Urinary Epithelial Cell Adhesion Molecule (EpCAM) as a Noninvasive Biomarker for Detecting Clinically Significant Prostate Cancer in Men With Equivocal PSA Levels

Background Prostate‐specific antigen (PSA) is widely used for prostate cancer screening, but its limited specificity in the diagnostic “grey zone” (4–10 ng/mL) results in unnecessary biopsies. This study evaluated urinary epithelial cell adhesion molecule (EpCAM), normalised to urinary creatinine, as a noninvasive biomarker for identifying clinically significant prostate cancer (csPCa) in men with equivocal PSA levels. Methods This cross‐sectional study included 286 men with PSA levels of 4–10 ng/mL scheduled for prostate biopsy. Histopathological outcomes were classified using ISUP Grade Groups. Urinary EpCAM was quantified by ELISA, and diagnostic performance for csPCa was assessed using nonparametric analyses, ROC curves and logistic regression. Results Urinary EpCAM/Cr levels increased significantly across diagnostic categories and were highest in men with csPCa ( p < 0.001). EpCAM/Cr showed strong discrimination for csPCa (AUC = 0.816), outperforming serum PSA and PSA density. In multivariable analysis, EpCAM/Cr (aOR = 1.07; 95% CI: 1.02–1.14; p = 0.009) and PSA density (aOR = 1.81; 95% CI: 1.20–3.18; p = 0.013) were independent predictors of csPCa, and EpCAM/Cr correlated positively with tumour aggressiveness ( ρ = 0.609; p < 0.001). Conclusion Urinary EpCAM/Cr shows promise as a noninvasive biomarker for detecting csPCa in men with PSA levels in the diagnostic grey zone.