Use of the MyProstateScore (MPS) Test to Rule Out Clinically-Significant Cancer: Validation of a Straightforward Clinical Testing Approach.

PURPOSE: The MyProstateScore (MPS) test was validated for improved detection of clinically-significant (Grade Group [GG] ≥2) prostate cancer relative to PSA-based risk calculators. We sought to validate an optimal MPS threshold for clinical use in ruling-out GG ≥2 cancer in men referred for biopsy.

MATERIALS AND METHODS: Biopsy-naïve men provided post-digital rectal examination (DRE) urine prior to biopsy. MPS was calculated using the validated, locked multivariable model including only serum PSA, urinary PCA3, and urinary TMPRSS2:ERG. The MPS threshold approximating 95% sensitivity for GG ≥2 cancer was identified in a training cohort, and performance was measured in two external validation cohorts. We assessed the (i) overall biopsy-referral population and (ii) population meeting guideline-based testing criteria (ie, PSA 3-10; or PSA <3 with suspicious DRE).

RESULTS: Validation cohorts were prospectively-enrolled from academic (n=977, median PSA 4.5 [IQR:3.1-6.0]) and community (n=548, median PSA 4.9 [IQR:3.7-6.8]) settings. In the overall validation population (n=1525), 338 men (22%) had GG ≥2 cancer on biopsy. The MPS threshold of 10 provided 97% sensitivity and 98% negative predictive value (NPV) for GG ≥2 cancer. MPS testing would have prevented 387 unnecessary biopsies (33%), while missing only ten GG ≥2 cancers (3.0%). In 1242 patients meeting guideline-based criteria, MPS ≤10 provided 96% sensitivity, 97% NPV, and would have prevented 32% of unnecessary biopsies, missing 3.7% of GG ≥2 cancers.

CONCLUSIONS: In a large, clinically-pertinent biopsy-referral population, MPS ≤10 provided exceptional sensitivity and NPV for ruling-out GG ≥2 cancer. This straightforward secondary testing approach would reduce the use of more costly and invasive procedures after screening with PSA.