Impact of the MyProstateScore (MPS) test on the clinical decision to undergo prostate biopsy: results from a contemporary academic practice

Abstract

AbstractObjectiveTo evaluate the association of the MyProstateScore (MPS) urine test on the decision to undergo biopsy in men referred for prostate biopsy at a contemporary academic urology practice.MethodsMPS testing was offered as an alternative to immediate biopsy in men referred to the University of Michigan for prostate biopsy from October 2013 through October 2016. The primary endpoint was the decision to perform biopsy. The proportion of patients who underwent biopsy was calculated across MPS quintiles and compared to predicted risk scores from the Prostate Cancer Prevention Trial risk calculator (PCPTrc). Analyses were performed in the overall referral population and the intended-use population (PSA 3-10 ng/ml or PSA <3 ng/ml and abnormal DRE) and stratified by the use of multiparametric magnetic resonance imaging (mpMRI). The associations of PCPTrc, MPS, and mpMRI with the decision to undergo biopsy were explored in a multivariable logistic regression model.ResultsOf 248 patients, 134 (54%) proceeded to prostate biopsy. Clinical variables, PSA, and PCPTrc score did not significantly differ based on the decision to undergo biopsy, while MPS was significantly higher in biopsied patients (median 29 vs. 14, p<0.001). The use of biopsy was strongly associated with MPS, with biopsy rates of 26%, 38%, 58%, 90%, and 85% in the first through fifth MPS quintiles, respectively (p<0.001). By contrast, biopsy rates were 51%, 47%, 52%, 69%, and 52% by increasing PCPTrc score quintile (p=0.3). The association of MPS with biopsy persisted upon stratification by use of mpMRI. On multivariable analysis, MPS was strongly associated with the decision to undergo biopsy when modeled as both a continuous variable (odds ratio [OR] 1.05 per 1 unit increase, 95% confidence interval [CI] 1.04-1.08; <0.001) and binary variable (OR 7.76, 95% CI 4.14-14.5; p<0.001). These findings were consistent in the overall and intended-use populations.ConclusionIn a cohort of patients who underwent clinical MPS testing as an alternative to immediate prostate biopsy, 46% were able to avoid biopsy and increasing MPS was strongly associated with biopsy rates. These findings were robust to the use of mpMRI and consistent across pertinent subpopulations. Overall, these data suggest that the MPS assay may substantially reduce the number of men undergoing prostate needle biopsy.