Determination of the PSA Cut-off Value to Predict the Clinically Significant Prostate Cancer in Patients with Positive Multiparametric MRI: A Population-based Study

Objective: In this study, we investigated the correlation between prostate imaging reporting and data scoring system (PIRADS) grades of patients' prostate lesions detected by multiparametric prostate magnetic resonance imaging (MpMRI) and prostate specific antigen (PSA) values obtained before prostate biopsy and its role in predicting clinically significant cancer in prostatectomy specimens. Materials and Methods: Patients who underwent biopsy and were diagnosed with prostate cancer (PCa) because of positive or negative MpMRI were evaluated. Histopathological factors were recorded, and the relationship between the PIRADS grading system and PSA values was analyzed in patients who underwent radical prostatectomy and preoperative MpMRI. PSA cut-off values predicting clinically significant PCa (CSPCa) in MpMRI were calculated. Results: A total of 1,319 patients were included in the study. MR-fusion biopsy was performed in 58% of the patients, and malignant histopathology was detected in 49% of the patients. While 87% of the patients had CSPCa, 13% had clinically insignificant PCa. The sensitivity and specificity of the PSA 4 ng/mL cut-off value were 88.6% and 15.1% in all patient groups, respectively. In predicting CSPCa, sensitivity was 88.9% and specificity was 18.8% for PSA 4 ng/mL cut-off value in MpMRI-negative patients. If PSA >4 ng/mL in MpMRI-negative patients, there is a >45% PCa detection rate in biopsy, but biopsy is more appropriate for PSA >10 ng/mL for CSPCa. In MpMRI-positive patients, if PSA is >2.5 ng/mL, biopsy provides a >50% PCa and >30% CSPCa diagnosis. If there are PIRADS 5 lesions and PSA is >2.5 ng/mL, biopsy has a >70% PCa and >60% CSPCa detection rate. Conclusions: It may be appropriate to consider higher PSA cut-off values (PSA >10 ng/mL) to make a biopsy decision in patients with negative MpMRI, whereas it may be possible to detect CSPCa at lower PSA values in patients with positive MpMRI findings and high PIRADS grade.