ABSTRACT
PURPOSE: Investigate the intermediate-term oncological outcome after negative multiparametric MRI (mpMRI) of the prostate in patients without biopsy proven prostate cancer (PCa). METHODS: The retrospective study included 121 patients with negative mpMRI (Prostate Imaging Reporting and Data System version 2.1 category<3) performed at our institution between 2012 and 2017 without known biopsy proven PCa. Clinical and pathological data were collated including post-MRI prostatic tissue diagnoses with highest Grade Group and most recent prostate specific antigen (PSA) levels up to any definitive prostate cancer treatment. Mean PSA velocities between patients with and without a subsequent diagnosis of Grade Group 2 or higher (GG2+) PCa were compared, and an optimal threshold value was calculated. RESULTS: Outcome data available included PSA values in 117 patients and prostate tissue sampling in 52 patients. Over a median follow up interval of 49.8 months, only 11 of 121 patients (9.1%) were diagnosed with GG2+ PCa, 10 patients (8.3%) with GG1 PCa, and 31 patients (25.6%) had negative prostate tissue samples. Mean PSA velocity was significantly higher in the patients diagnosed with GG2+ PCa (3.87 ng/mL/year) compared to those not diagnosed with GG2+ PCa (-0.71 ng/mL/year, p < 0.001). A threshold PSA velocity of 0.27 ng/mL/year had a 100% sensitivity and 69.8% specificity for GG2+ PCa (AUC: 0.898). CONCLUSION: <10% of patients with negative mpMRI without prior biopsy proven PCa were diagnosed with GG2+ PCa over median follow up of over four years and were associated with PSA velocity of ≥0.27 ng/mL/year. PSA monitoring may be a reasonable management strategy in patients with a negative mpMRI without biopsy proven PCa.
