Magnetic Resonance Imaging-guided Active Surveillance Without Annual Rebiopsy in Patients with Grade Group 1 or 2 Prostate Cancer: The Prospective PROMM-AS Study

In this prospective magnetic resonance imaging (MRI)-guided surveillance protocol for patients with grade group (GG) 1 or GG 2 prostate cancer, MRI was used to stratify patients according to disease progression or stability. Among men with GG 1 cancer, 88% of biopsies were avoided. Among cases with MRI progression, active surveillance was correctly terminated for 81% of men with GG 1 and 91% of men with GG 2 cancer. Multiparametric magnetic resonance imaging (mpMRI) may allow patients with prostate cancer (PC) on active surveillance (AS) to avoid repeat prostate biopsies during monitoring. To assess the ability of mpMRI to reduce guideline-mandated biopsy and to predict grade group upgrading in patients with International Society of Urological Pathology grade group (GG) 1 or GG 2 PC using Prostate Cancer Radiological Estimation of Change in Sequential Evaluation (PRECISE) scores. The hypothesis was that the AS disqualification rate (ASDQ) rate could be reduced to 15%. Design, setting and participants: PROMM-AS was a prospective study assessing 2-yr outcomes for an mpMRI-guided AS protocol. A 12 mo after AS inclusion on the basis of MRI/transrectal ultrasound fusion-guided biopsy (FBx), all patients underwent mpMRI. For patients with stable mpMRI (PRECISE 1–3), repeat biopsy was deferred and follow-up mpMRI was scheduled for 12 mo later. Patients with mpMRI progression (PRECISE 4–5) underwent FBx. At the end of the study, follow-up FBx was indicated for all patients. Outcome measurements and statistical analysis: We calculated the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for upgrading to GG 2 in the GG 1 group, and to GG 3 in the GG 2 group on MRI. We performed regression analyses that included clinical variables. The study included 101 patients with PC (60 GG 1 and 41 GG 2). Histopathological progression occurred in 31 patients, 18 in the GG 1 group and 13 in the GG 2 group. Thus, the aim of reducing the ASDQ rate to 15% was not achieved. The sensitivity, specificity, PPV, and NPV for PRECISE scoring of MRI were 94%, 64%, 81%, and 88% in the GG 1 group, and 92%, 50%, 92%, and 50%, respectively, in the GG 2 group. On regression analysis, initial prostate-specific antigen (p < 0.001) and higher PRECISE score (4–5; p = 0.005) were significant predictors of histological progression of GG 1 PC. Higher PRECISE score (p = 0.009), initial Prostate Imaging-Reporting and Data System score (p = 0.009), previous ne