A study sought to determine predictors for grade group (GG) reclassification in patients undergoing an magnetic resonance imaging (MRI)-informed prostate biopsy (MRI-Bx) during active surveillance (AS) for prostate cancer, and to evaluate whether a confirmatory biopsy could be omitted in patients diagnosed with upfront MRI. The findings were reported in European Urology Oncology.
Researchers assessed 1,185 patients from the Prostate cancer Research International: Active Surveillance (PRIAS) study, a multicenter prospective study of patients on AS. Time-dependent Cox regression analysis was used to discern predictors of GG progression/reclassification in patients undergoing MRI-Bx.
According to the analysis, age (per 10 year, hazard ratio [HR] = 0.84; 95% confidence interval [CI], 0.71–0.99]), MRI outcome (Prostate Imaging Reporting and Data System [PIRADS] 3 vs. negative HR = 2.46; 95% CI, 1.56–3.88, PIRADS 4 vs. negative HR = 3.39; 95% CI, 2.28–5.05; and PIRADS 5 vs. negative HR = 4.95; 95% CI, 3.25–7.56), prostate-specific antigen (PSA) density (per 0.1 ng/ml cm3; HR = 1.20; 95% CI, 1.12–1.30), and percentage positive cores on the last systematic biopsy (per 10%; HR = 1.16; 95% CI, 1.10–1.23) were significant predictors of GG reclassification.
The researchers concluded that a “protocol-based prostate biopsy while on active surveillance can be omitted in patients with negative magnetic resonance imaging (MRI) and prostate-specific antigen density <0.15 ng/ml cm3. A confirmatory biopsy cannot simply be omitted in all patients diagnosed with upfront MRI.”