Association between urology practice use of multiparametric MRI and genomic testing and treatment of men with newly diagnosed prostate cancer.

INTRODUCTION: Biomarkers for prostate cancer, such as multiparametric MRI (mpMRI) and tissue-based genomics, are increasingly used for treatment decision-making. Using biomarkers indiscriminately and thus ignoring competing risks of mortality may lead to treatment in some men who derive little clinical benefit. We assessed the relationship between urology practice use of biomarkers and subsequent treatment in men with newly diagnosed prostate cancer. METHODS: We used a 20% random sample of national Medicare data to perform a retrospective cohort study of men with newly diagnosed prostate cancer diagnosed from 2015 through 2019. Urology practice-level use of biomarkers was characterized based on urology practice propensity to use either biomarker after diagnosis (never, below median, above the median). Noncancer mortality risk within 10 years of diagnosis was calculated for all men. Multilevel models were used to assess the relationship between practice-level biomarker use and treatment by noncancer mortality risk. RESULTS: Between 2015 and 2019, 1,764 (65%) urology practices used mpMRI and 897 (33%) used genomic testing for prostate cancer. Compared with urology practices never using each biomarker, those using mpMRI above the median (56% vs. 47%, P = 0.003) and tissue-based genomics below the median (56% vs. 50%, P = 0.03) were more likely to treat men with >75% risk of noncancer mortality. Additionally, compared with urology practices never using either biomarker, use of mpMRI (72% vs. 69%, P = 0.07) or tissue-based genomics (71% vs. 70%, P = 0.65) did not impact treatment in the healthiest group (i.e., those with <25% risk of noncancer mortality). CONCLUSIONS: Compared to practices that do not use each biomarker in men with newly diagnosed prostate cancer, urology practices using mpMRI, and tissue-based genomics to a lesser extent, are more likely to treat men at very high risk of dying from competing risks of mortality within 10 years of prostate cancer diagnosis.