How to optimize follow-up in patients with a suspicious multiparametric MRI and a subsequent negative targeted prostate biopsy. Results from a large, single-institution series

Abstract

Objective: We aimed at optimizing the follow-up for patients with a positive multiparametric magnetic resonance of the prostate (mpMRI) and a subsequent negative targeted biopsy (TBx) plus systematic biopsy (SBx).

Materials and methods: A total of 308 men with a clinical suspicion of PCa and a positive mpMRI (PI-RADS ≥ 3) with concomitant negative systematic and targeted Bx performed at a single tertiary referral center. All patients were then followed with serial PSA measurements, digital rectal examination and eventual follow-up mpMRI and/or repeat Bx. The primary outcome was to evaluate the overall clinically significant PCa (csPCa)-free survival. The secondary outcome was to assess the role of a repeat mpMRI (Fu-mpMRI) and PSA density as predictors of csPCa diagnosis (defined as Gleason score ≥ 3 + 4) during follow-up. Kaplan Meier analysis and univariable Cox regression were used for survival and predictive analyses.

Results: Median follow-up was 31 months (IQR: 23-43). During the study period 116 (37.7%) and 68 (22.1%) of men received a Fu-mpMRI and a Fu-Bx, respectively. Overall, 51 (16.6%) and 15 (4.9%) patients had a positive mpMRI and clinically significant (csPCa) diagnosis during follow-up, respectively. Among 68 men who received a Fu-Bx, the 2- and 3-years csPCa diagnosis-free survival in men with negative vs. positive Fu-mpMRI was 97% vs. 65% and 92% vs. 65%, respectively. At univariate Cox-regression analysis the presence of a positive Fu-mpMRI resulted to be significantly associated with the presence of csPCa at Fu-Bx (HR: 5.8, 95% CI: 1.3-26.6, P = 0.008). The 2- and 3-years csPCa diagnosis-free survival in men with PSAd <0.15 vs. ≥0.15 was 89% vs. 77%, and 86% vs. 66%, respectively (HR: 2.6, 95% CI: 0.75-8.87, P = 0.13). The combination of negative Fu-mpMRI and PSAd<0.15 furtherly reduced the probability of csPCa diagnosis at Fu-Bx at only 6% at 3years (HR: 9.9, 95% CI: 1.9-38.6, P < 0.001) in this subgroup of patients.

Conclusions: After a negative TBx for a positive mpMRI, more than half of Fu-mpMRI were negative. A persistent positive mpMRI was associated with a significant risk of csPCa. The risk of csPCa diagnosis in men with negative mpMRI performed after negative TBx and low PSAd was negligible.

Keywords: Biopsy; Diagnosis; Follow-up; MRI; Prostate cancer; Targeted biopsy.