The presence of prostate MRI-visible lesions at follow-up biopsy as a risk factor for histopathological upgrading during active surveillance.

Objective: To prospectively determine the ability of visible lesions on multiparametric MRI (PI-RADS 4-5) and commonly used biomarkers to predict disease upgrading on rebiopsy in men with low-risk prostate cancer (PCa) enrolled in active surveillance (AS).

Methods: For this prospective study, approved by the Institutional Review Board (IRB), we selected consecutive patients with low-risk, low-grade, and localized prostate cancer (PCa) from our active surveillance (AS) program, who were enrolled between March 2014 and December 2020. Patients who had undergone previous prostate surgery, hormonal treatment, had contraindications for mpMRI, or transrectal ultrasound-guided (TRUS) biopsy were excluded from this study. All eligible patients underwent mpMRI at least 3 months after the initial biopsy, followed by MRI-targeted TRUS-guided re-biopsy within 12 months after enrollment. The mpMRI studies were evaluated by an experienced radiologist using the PI-RADS v2 classification. Statistical significance was determined by comparing the results from the MRI with the pathology data from rebiopsy.

Results: There were 240 patients included. Overall upgrading rate was 41.2% (99/240), higher among patients classified as PIRADS 4 or 5 (77%). MRI sensitivity was 77.7% and specificity was 83.6% on re-biopsy. Visible lesion on mpMRI, PSA density and 3 + /12 positive cores at the first biopsy were good predictors of disease upgrade on rebiopsy. On our predictive model, patients with PI-RADS 4 or 5, PSA density > 0.15 ng/mL/cm3, and 3 + /12 positive cores at first biopsy had 92.4% chance of having clinically significant PCa.

Conclusions: Patients in AS with PI-RADS 4 or 5 lesions, PSA density > 0.15 ng/mL/cm3 and 3 + /12 positive cores at first biopsy have a high probability of having significant PCa on re-biopsy.