#0205

Reducing Unnecessary Biopsies in PI-RADS 3-4 Lesions Through PSA-Derived Biomarker Integration: A Decision Curve Analysis

J. Kuo¹, Y. Ou¹, C. Hu¹, K. Wu¹, C. Liu¹, H. Jan¹, K. Lin¹, Y. Hsieh¹, C. Ou¹, Y. Tsai¹

¹National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Department of Urology, Tainan, Taiwan

Introduction:

Prostate cancer (PCa) is a leading malignancy among men, yet identifying clinically significant PCa (csPCa) remains challenging. Despite advances with mpMRI and PI-RADS scoring, PI-RADS 3 and 4 lesions still result in potentially unnecessary biopsies. This study explores whether integrating PSA-based biomarkers and clinical parameters can improve risk assessment and minimize avoidable interventions in a Taiwanese cohort.

Material and methods:

Detailed medical records of 165 patients who underwent mpMRI and MRI-ultrasound fusion-guided biopsy between April 2021 and August 2024 were retrospectively reviewed. Patients were stratified into PI-RADS 3-4 and PI-RADS 5 groups. csPCa was defined as an ISUP grade ≥2. Logistic regression models were used to identify predictors of csPCa. The diagnostic performance of PI-RADS alone and in combination with PSA density (PSAD) and PSA velocity (PSAV) was assessed using receiver operating characteristic (ROC) analysis and decision curve analysis (DCA).

Results:

csPCa was detected in 30.8% of PI-RADS 3-4 lesions. PSAD ≥0.20 ng/mL/mL was an independent predictor of csPCa (OR: 12.167, p = 0.042). In the overall cohort, the combination of PI-RADS 3-4 with PSAD ≥0.20 ng/mL/mL and PSAV ≥0.75 ng/mL/year improved diagnostic accuracy (AUC: 0.624) compared to PI-RADS alone. In the PI-RADS 3-4 subgroup, the combined model achieved an AUC of 0.673. DCA demonstrated that this combined model provided the highest net benefit within a threshold probability range of 25%-50%, reducing unnecessary biopsies by approximately 40%. In the PI-RADS 3-4 subgroup, the combination model also yielded the greatest net benefit within the threshold range of 18%-50%.