Cancer-specific outcomes for prostate cancer patients who had prebiopsy prostate MRI

We characterized population-level cancer-specific outcomes for prostate cancer patients based on use of prebiopsy prostate MRI.

Using SEER-Medicare claims, we identified men diagnosed with localized prostate cancer from 2010-2015 and prostate-specific antigen (PSA) < 20 ng/mL. Primary exposure was prebiopsy prostate MRI prior to diagnosis (i.e., CPT 72197 linked to urology-specific diagnosis). Outcomes included diagnosis of Grade Group 2+ disease on biopsy and proportion treated with prostatectomy. We assessed those treated with prostatectomy and evaluated association with prebiopsy MRI and grade concordance between biopsy and prostatectomy. We estimated adjusted odds ratios with multivariable regression after accounting for other factors (e.g., age, year, PSA, race/ethnicity).

We identified 48,574 patients, where 915 (1.9%) underwent prebiopsy MRI. Patients with prebiopsy MRI had more GG>2 cancer on biopsy (70.0% MRI vs. 62.8% no MRI) but lost significance after adjustment (OR 1.12, 95% CI 0.96-1.30). Patients with prebiopsy MRI were more likely to have prostatectomy (39.2% vs. 28.5%, adjusted OR 1.51, 95%CI 1.31-1.76). Downgrading from biopsy GG 3-5 to final GG 1-2 was less common after prebiopsy MRI (21.3% vs. 28.2% no MRI, P = 0.05) but not significant after adjustment (OR 0.74, 95% CI 0.51 - 1.08). Among 14,027 men with prostatectomy, accurate risk classification was not more likely with a prebiopsy MRI (48.0% no MRI vs. 49.6% prebiopsy MRI, P = 0.56).

During initial adoption, men with prebiopsy prostate MRI had marginally increased detection of significant cancer on biopsy and were more likely to be treated with prostatectomy. For those treated with prostatectomy, use of prebiopsy MRI was not associated with a greater likelihood of accurate risk classification or grade concordance between biopsy and final pathology results.