Impact of prebiopsy magnetic resonance imaging of the prostate on cancer detection and treatment patterns.

PURPOSE: Though superior in clinical trial settings, outcomes following magnetic resonance image (MRI)-guided prostate biopsies have not been reported broadly. We compared prostate cancer detection rates for men who did and did not undergo prebiopsy MRI and evaluated treatment patterns based on biopsy approach, year of biopsy, and proximity to early adopters.

METHODS: Using private insurance claims (2009-2015), we identified men who underwent prostate biopsy using appropriate procedure codes. Exposure was receipt of prebiopsy MRI within 3 months prior to biopsy. Outcomes included new prostate cancer diagnosis, treatment with prostatectomy/radiation, and receipt of adjunct procedures typically used for higher-risk disease (i.e., lymphadenectomy with prostatectomy, androgen deprivation therapy with radiation). Hierarchical mixed-effects multivariable logistic regression predicted probabilities of each outcome.

RESULTS: We identified 77,350 men (mean age 57.5 ± 5.4 years) who underwent biopsy with 12% having had a prior negative biopsy. Use of prebiopsy MRI was more common among men biopsied from 2014 to 2015 (4.4% vs. 1.3% 2012-2013), in metropolitan statistical areas (2.6% vs. 1.1% not), residing close to early adopters (5.5% vs. 1.5% far), and with prior negative biopsy (7.3% vs. 1.7% biopsy-naïve; all P < 0.001). Compared to patients with a prior negative biopsy and no MRI, men were more likely to be diagnosed with prostate cancer if they had a prior negative biopsy and MRI (24.7% vs. 21.4% prior negative without MRI, odds ratio 1.25, 95% confidence interval 1.04-1.51) or an initial biopsy without prior MRI (40.0% vs. 21.4% prior negative without MRI, odds ratio 2.49, 95% confidence interval 2.36-2.64; P < 0.001). Predicted probability of treatment overall and adjunct treatment did not differ based on receipt of pre-biopsy MRI.

CONCLUSIONS: Among privately insured men in the United States, use of prostate MRI prior to prostate biopsy was associated with increased cancer detection among those with prior negative biopsies, but we did not observe significant changes with downstream treatment patterns.