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Multi-parametric MRI-targeted biopsy compared to systematic TRUS biopsy for biopsy-naïve men at risk for prostate cancer: 2 year follow up data and economic analysis

Introduction & Objectives

Introduction: The Precise study, a prospective randomized trial, demonstrated that MRI with only targeted biopsy was non-inferior to systematic TRUS guided biopsies in the detection of ISUP GG ≥2 prostate cancer. An unanswered question is the outcome in those patients who avoided a biopsy due to a negative MRI. Objective: We sought to address the outcome of patients on this trial who were unbiopsied, or had a negative or GG1 targeted biopsy, compared to those whose systematic biopsy was negative or GG1, with respect to the rate of subsequent PCa diagnosis based on a 2 year MRI +/- targeted biopsy performed in all patients. In addition, we used administrative provincial data to compare the net costs of the two strategies.

Materials & Methods

Methods: The study was carried out at 5 Canadian centres. The Precise trial randomized 453 biopsy-naïve men with a clinical suspicion of prostate cancer, advised to have a prostate biopsy. All those not diagnosed with GG ≥2 prostate cancer (unbiopsied due to a negative MRI, or a negative biopsy, or GG1 disease if biopsied) were entered in the follow up study. All Ontario patients were entered in the economic analysis. Intervention: 2 year MRI in all men (both MRI and systematic biopsy groups). Targeted biopsy was performed for Pi-RADS ≥ 3 or for clinical suspicion. Main Outcome: The proportion of men diagnosed with GG ≥ 2 cancer. Secondary outcomes included the MRI outcome, the proportions diagnosed with GG1 PCa, and subsequent hospitalization rates.


Results: 73 patients in the MRI arm and 69 patients in the systematic biopsy arm had a 2 year evaluable MRI. In the MRI and systematic bx arm, 70% and 72% had a negative 2 year MRI. Of the 16 patients in the systematic biopsy arm who had a 2 year biopsy, 8 were negative, 2 were GG1, and 6 were GG ≥2. In the MRI arm, 8 were biopsied; 4 were negative, and 4 were GG ≥2. At 2 years, in the Systematic Bx and MRI groups, 27% and 30% either were diagnosed with GG ≥2 disease; treated, died, or progressed. 15% from the TRUS biopsy group had a hospital visit after biopsy compared to less 6% from the MRI group. The mean per person per year (PPPY) costs for the TRUS and All MRI groups (MRI- and MRI+) were $7,828 and $8,525, respectively.


Conclusion: After 2 years of follow up including an MRI +/- biopsy in both groups, there was no difference in the rate of CS PCa diagnosis between the MRI with only targeted biopsy, and systematic biopsy groups, despite 40% of men in the initial MRI group avoiding biopsy. Economic analysis using a linked provincial databased demonstrated no significant difference in net cost between the 2 strategies. These results confirm the safety and cost effectiveness of an imaging first diagnostic strategy. Registration: ClinicalTrials.gov Identifier: NCT02936258.