Frequency of Biopsy and Tumor Grade Before vs After Introduction of Prostate Magnetic Resonance Imaging.

Importance: In randomized clinical trials (RCTs), magnetic resonance imaging (MRI) before prostate biopsy has been associated with fewer biopsies, decreased detection of Gleason score 6 cancers, and increased detection of Gleason score 7 or higher cancers. Objective: To study whether MRI of the prostate before the decision to biopsy is associated with biopsy frequency and distribution of Gleason score in clinical practice. Design, Setting, and Participants: This is a retrospective, population-based cohort study of men in Jönköping Region, Sweden. Men with prostate-specific antigen (PSA) level measured between November 2011 and 2020 were monitored until January 31, 2021. Men with known prostate cancer were excluded. Data analysis was performed from July to December 2022. Exposures: Data on repeated PSA measures, prostate biopsies, and MRI prostate were extracted from health care records, and cancer characteristics were obtained from The National Prostate Cancer Register. Main Outcomes and Measures: The proportions of men who underwent prostate biopsy and risk of Gleason score 6 or Gleason score 7 or higher cancer and negative biopsy before and after introduction of MRI were calculated. Results: In this cohort study of 23 802 men (mean [SD] age, 60.8 [13.6] years) who underwent PSA testing, when the use of MRI increased, fewer biopsies were performed (adjusted odds ratio [OR], 0.84; 95% CI, 0.72-0.97) and the odds of detecting Gleason score 6 cancer decreased (OR, 0.47; 95% CI, 0.33-0.64), whereas the odds of detecting Gleason score 7 or higher cancer increased (OR, 1.24; 95% CI, 1.02-1.50). Conclusions and Relevance: In this study, the introduction of MRI to clinical practice was associated with a decreased proportion of men who underwent a biopsy and decreased detection of Gleason score 6 cancer but increased detection of Gleason score 7 or higher cancer. These clinical data support the use of prostate MRI before biopsy in an effort to avoid unnecessary biopsies.