To examine practice-level variation in the management of magnetic resonance imaging (MRI) Prostate Imaging-Reporting and Data System (PI-RADS) 3 lesions in men with favorable-risk prostate cancer (FRPC) considering or on active surveillance (AS).

We reviewed the Michigan Urological Surgery Improvement Collaborative registry for FRPC men (GG1 and low-volume GG2) undergoing MRI from January 2013 to March 2020. The primary outcome was to assess practice-level variation in time from MRI to biopsy and MRI to treatment for PI-RADS 3 lesions. Both MRIs obtained after the diagnostic biopsy and while on AS were included. The Kaplan-Meier method was used to estimate biopsy-free survival for time from MRI to surveillance biopsy and multivariable Cox proportional hazards models identified clinical and demographic factors associated with time obtaining a biopsy after finding PI-RADS 3 lesions.

We identified 3172 FRPC men with a MRI, of whom 473 had a PI-RADS 3. There was significant practice-level variation in biopsy rates among patients with PI-RADS 3 MRI results (log-rank test, P <.001), with biopsy-free probability at 6 months ranging from 28% to 69% (median: 59%). We were unable to identify factors with significant associations with time to biopsy. Conversely, there was less variation in time from PI-RADS 3 to treatment (log-rank test, P = .2), while several clinical factors had statistically-significant associations: age (P = .018), Prostate Specific Antigen-Density 0.1-0.2 (P = .035), ISUP-GG 2 (P = .002), and number of positive cores (P <.001), as expected.

Urology practice, rather than GG or extent of biopsy positivity, is the largest factor affecting the decision for biopsy of PI-RADS 3 lesions in FRPC men considering or on AS. Future work to assist with decision-making and reduce variability is needed.