The 18-gene MyProstateScore 2.0 (MPS2) test was previously validated for detection of grade group (GG) ≥ 2 prostate cancer using post-digital rectal examination (DRE) urine. To improve ease of testing, we validated MPS2 using first-catch, non-DRE urine. Patients provided first-catch urine before biopsy. MPS2 values were calculated using previously validated models differing only by extent of clinical data included biomarkers alone (BA; no clinical data), biomarkers and clinical factors (BA + CF), and biomarkers, clinical factors, and prostate volume (BA + CF + PV). The primary outcome was GG ≥ 2 cancer on biopsy. MPS2 performance and clinical consequences of testing were compared with PSA and the Prostate Cancer Prevention Trial risk calculator (PCPTrc). The cohort included 266 men with median PSA 6.6 ng/mL (IQR, 4.9-9.1) of whom 103 (39%) had GG ≥ 2 cancer on biopsy. The AUC for GG ≥ 2 cancer was 57% for PSA, 62% for PCPTrc, and 71%, 74%, and 77% for MPS2 models. Under a testing approach detecting > 90% of GG ≥ 2 cancers, MPS2 testing would have avoided 36% to 42% of unnecessary biopsies, as compared with 13% using the PCPTrc. In patients with a prior negative biopsy, MPS2 testing would have avoided 44% to 53% of repeat biopsies, as compared with only 2.6% using PCPTrc. Using first-catch urine, MPS2 meaningfully improved the proportion of biopsies avoided relative to PCPTrc while maintaining highly sensitive detection of GG ≥ 2 cancer. Non-DRE testing provides a convenient, objective, and highly accurate testing option to reduce the need for imaging and biopsy in men with elevated PSA.
Background/Objectives: Prostate cancer (PCa) is a leading cause of cancer-related deaths among men, with early detection playing a crucial role in improving outcomes. MyProstateScore 2.0 (MPS2), a novel urinary biomarker test, predicts clinically significant PCa to reduce invasive biopsy procedures. This study evaluates the analytical performance of MPS2 using both a post-digital rectal exam (DRE) and non-DRE urine samples. Methods: We assessed the reproducibility, precision, and detection limits of the eighteen MPS2 analytes. Analytical parameters including the linear range, upper and lower limits of quantification (ULOQ and LLOQ), and interference from substances commonly present in urine were evaluated. The reproducibility of the MPS2 scores was evaluated across post-DRE and non-DRE clinical urine samples. Results: MPS2 analytes demonstrated high linearity (R2 ≥ 0.975) across defined quantification ranges, with PCR efficiencies of 97–105%. The limits of detection (LOD) ranged from 40 to 160 copies/reaction, while the ULOQ was determined to be 106–107 copies/reaction for each analyte. Precision studies showed intra-run, inter-run, and inter-instrument standard deviations ≤0.5 Crt. Among the 12 potential interfering substances, only whole blood affected the performance of MPS2. The reproducibility of the MPS2 scores was consistent across post-DRE and non-DRE urine samples, meeting the acceptance criteria. Conclusions: The analytical validation confirms that MPS2 is robust and reliable in detecting biomarkers for clinically significant PCa. These findings, coupled with previous clinical validations, support the clinical use of MPS2 as a non-invasive diagnostic tool.
Background/Objectives: Active surveillance (AS) is recommended for men with low-risk prostate cancer to minimize overtreatment while monitoring for disease progression. However, current surveillance strategies rely heavily on repeat biopsies, which are invasive and associated with morbidity. MyProstateScore 2.0—Active Surveillance (MPS2-AS) is a urine-based biomarker test developed to predict progression to Grade Group ≥ 2 (GG ≥ 2) and Grade Group ≥ 3 (GG ≥ 3) prostate cancers in men on AS. The objective of this study was to analytically validate the reproducibility and robustness of MPS2-AS analyte detection and risk score calculation across key laboratory variables. Methods: Analytical precision was evaluated using pooled urine specimens processed using the MPS2-AS laboratory workflow. Eight pooled urine samples were tested in a within-laboratory design across five days, with two runs per day, and two replicates per run. Additional reproducibility studies assessed variability across three QuantStudio™ 12K Flex Real-Time PCR Systems and three OpenArray™ chip lots. Ten RNA biomarkers were quantified by RT-PCR and used to calculate the MPS2-AS GG1-2 and GG1-3 risk scores. Variance components were estimated using hierarchical ANOVA. Results: The MPS2-AS analyte measurements demonstrated high precision across within-laboratory testing, with standard deviations ranging from 0.00 to 0.60 and coefficients of variation (%CV) from 0.00 to 4.01%. The reproducibility across qPCR instruments and OpenArray chip lots showed similar robustness, with analyte %CVs of ≤4.57% and ≤4.10%, respectively. These stable analyte measurements translated to reproducible model outputs, with %CV ≤ 10.69% for the GG1-2 risk score and ≤7.20% for the GG1-3 risk score across all tested conditions. No systematic bias was observed between runs, days, instruments, or reagent lots. Conclusions: MPS2-AS demonstrates strong analytical precision and reproducibility for quantifying urinary biomarkers and generating GG1-2 and GG1-3 risk scores. These results support the reliability of MPS2-AS for clinical laboratory implementation and its use as a non-invasive tool to inform biopsy decisions in men with Grade Group 1 prostate cancer undergoing active surveillance.
Prostate cancer (PCa) remains the most common cancer and the second leading cause of cancer-related deaths among men in the United States. Early detection is critical, yet routine prostate-specific antigen (PSA) screening has shown limited benefits, often leading to unnecessary biopsies. MyProstateScore 2.0 (MPS2), a novel urinary 18-biomarker test, aims to improve the detection of clinically significant prostate cancer (csPCa) while minimizing the risk of unnecessary procedures. This study aims to validate the analytical performance of MPS2, including analytical detection limits, reproducibility, and robustness across various potential interfering substances. The limit of detection (LoD) and lower limit of quantitation (LLOQ) for the 18 MPS2 biomarkers ranged from 40 to 160 copies/reaction and 80 to 320 copies/reaction, respectively. The upper limit of quantitation (ULOQ) was determined to be up to 10^7 copies/reaction for most analytes. The linear amplification of MPS2 biomarker amplification was confirmed between the defined LLOQ and ULOQ. Eleven of 12 potential interfering substances tested had minimal impact on the assay. The exception was whole blood, which delayed biomarker detection. In conclusion, MPS2 exhibits robust analytical performance, with reliable detection and quantitation limits. This validation supports the clinical use of MPS2 for accurately predicting clinically-significant PCa, potentially reducing unnecessary biopsies and associated complications.