Independent Validation of a Diagnostic Noninvasive 3-MicroRNA Ratio Model ( uCaP) for Prostate Cancer in Cell-Free Urine

Clin Chem. 2019 Apr;65(4):540-548. doi: 10.1373/clinchem.2018.296681. Epub 2019 Feb 6.

Abstract

Background: Detection of prostate cancer (PC) based on serum prostate-specific antigen (PSA) testing leads to many unnecessary prostate biopsies, overdiagnosis, and overtreatment of clinically insignificant tumors. Thus, novel and more accurate molecular biomarkers are required.

Methods: Using reverse transcription quantitative PCR, we measured the concentrations of 45 preselected microRNAs (miRNAs) in extracellular vesicle-enriched cell-free urine samples from 4 independent patient cohorts from Spain and Denmark, including 758 patients with clinically localized PC, 289 noncancer controls with benign prostatic hyperplasia (BPH), and 233 patients undergoing initial transrectal ultrasound (TRUS)-guided prostate biopsy owing to PC suspicion (101 with benign and 132 with malignant outcome). Diagnostic potential was assessed by ROC and decision curve analysis.

Results: We identified and successfully validated 8 upregulated and 21 downregulated miRNAs in urine from PC patients. Furthermore, we validated a previously identified 3-miRNA diagnostic ratio model, uCaP (miR-222-3p*miR-24-3p/miR-30c-5p). High uCaP scores were distinctive of PC in urine samples from BPH vs PC patients in 3 independent cohorts [area under the curve (AUC) = 0.84, 0.71, 0.72]. Additionally, uCaP predicted TRUS biopsy results with greater accuracy than PSA (AUC uCaP = 0.644; AUC PSA = 0.527) for patients within the diagnostic gray zone (PSA ≤ 10 ng/mL).

Conclusions: We successfully validated a urine-based diagnostic 3-miRNA signature for PC (uCaP) in 3 independent patient cohorts from 2 countries. In the future, the simple and noninvasive uCaP test may be used to help more accurately select patients for prostate biopsy. Prospective clinical validation is warranted.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Area Under Curve
  • Biomarkers, Tumor / metabolism
  • Biomarkers, Tumor / urine*
  • Cohort Studies
  • Denmark
  • Down-Regulation
  • Humans
  • Male
  • MicroRNAs / metabolism
  • MicroRNAs / urine*
  • Middle Aged
  • Models, Biological
  • Prostatic Neoplasms / diagnosis*
  • Prostatic Neoplasms / metabolism
  • ROC Curve
  • Spain
  • Up-Regulation

Substances

  • Biomarkers, Tumor
  • MicroRNAs