T2:ERG and PCA3 RNA Urinary Testing for Detecting Aggressive Prostate Cancer


Key Points

  • Combined testing for urinary PCA3 and T2:ERG RNA preserved high sensitivity and improved specificity in the detection of aggressive prostate cancer.
  • It was estimated that 42% of unnecessary biopsies could be avoided with the use of the urine assay.

Combined testing for urinary PCA3 and TMPRSS2:ERG (T2:ERG) RNA may increase accuracy in identifying the risk for aggressive early prostate cancer, according to a study reported in JAMA Oncology by Sanda et al in the EDRN-PCA3 Study Group.

Study Details

The study involved 516 development cohort men and 561 validation cohort men presenting for first-time prostate biopsy (without known prostate cancer) at academic and community-based ambulatory urology clinics. Patients underwent combined measurement of PCA3 and T2:ERG RNA in the urine after digital rectal examination and before biopsy to determine whether such measurement would improve specificity over measurement of prostate-specific antigen alone for detecting cancer with a Gleason score of ≥ 7.

Sensitivity and Specificity

In the development cohort (mean age = 62 years, range = 33–85 years), a decision algorithm using urine RNA assays was used to optimize specificity while maintaining 95% sensitivity for predicting aggressive disease on initial biopsy. Combined testing of urinary T2:ERG and PCA3 at thresholds that maintained a 95% sensitivity improved specificity for aggressive disease from 18% to 39%. In the validation cohort (mean age = 62 years, range = 27–86 years), a sensitivity of 93% was preserved, whereas specificity improved from 17% to 33% (P = .04).

It was estimated that 42% of unnecessary prostate biopsies could be avoided with the use of the urine assay to select candidates for biopsy. Cost analysis indicated that use of the urinary testing algorithm to restrict prostate biopsy would provide greater cost-benefit among younger men.

The investigators concluded: “Combined urinary testing for T2:ERG and PCA3 can avert unnecessary biopsy while retaining robust sensitivity for detecting aggressive prostate cancer with consequent potential health care cost savings.”

The study was supported by grants from the National Institutes of Health and the A. Alfred Taubman Medical Research Institute.

Martin G. Sanda, MD, of Emory University School of Medicine, is the corresponding author of the JAMA Oncology article.

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.