A Multi-Institutional Prospective Trial Confirms Noninvasive Blood Test Maintains Predictive Value in African American Men

J Urol. 2018 Jun;199(6):1459-1463. doi: 10.1016/j.juro.2017.11.113. Epub 2017 Dec 6.


Purpose: The 4Kscore® test accurately detects aggressive prostate cancer and reduces unnecessary biopsies. However, its performance in African American men has been unknown. We assessed test performance in a cohort of men with a large African American representation.

Materials and methods: Men referred for prostate biopsy at 8 Veterans Affairs medical centers were prospectively enrolled in the study. All men underwent phlebotomy for 4Kscore test assessment prior to prostate biopsy. The primary outcome was the detection of Grade Group 2 or higher cancer on biopsy. We assessed the discrimination, calibration and clinical usefulness of 4Kscore to predict Grade Group 2 or higher prostate cancer and compared it to a base model consisting of age, digital rectal examination and prostate specific antigen. Additionally, we compared test performance in African American and nonAfrican American men.

Results: Of the 366 enrolled men 205 (56%) were African American and 131 (36%) had Grade Group 2 or higher prostate cancer. The 4Kscore test showed better discrimination (AUC 0.81 vs 0.74, p <0.01) and higher clinical usefulness on decision curve analysis than the base model. Test prediction closely approximated the observed risk of Grade Group 2 or higher prostate cancer. There was no difference in test performance in African American and nonAfrican American men (0.80 vs 0.84, p = 0.32), The test outperformed the base model in each group.

Conclusions: The 4Kscore test accurately predicts aggressive prostate cancer for biopsy decision making in African American and nonAfrican American men.

Keywords: African Americans; biomarkers; kallikreins; neoplasm grading; prostatic neoplasms; tumor.

Publication types

  • Clinical Trial
  • Multicenter Study

MeSH terms

  • Adenocarcinoma / blood
  • Adenocarcinoma / diagnosis*
  • Adenocarcinoma / pathology
  • African Americans / statistics & numerical data*
  • Aged
  • Biomarkers, Tumor / blood*
  • Biopsy
  • Clinical Decision-Making
  • Hospitals, Veterans / statistics & numerical data
  • Humans
  • Male
  • Middle Aged
  • Neoplasm Grading
  • Patient Selection
  • Predictive Value of Tests
  • Prognosis
  • Prospective Studies
  • Prostate / pathology*
  • Prostatic Neoplasms / blood
  • Prostatic Neoplasms / diagnosis*
  • Prostatic Neoplasms / pathology
  • Risk Assessment / methods
  • United States
  • United States Department of Veterans Affairs


  • Biomarkers, Tumor