Medical Reading

PCA3, A Urine Test For Prostate Cancer, Shows Increased Specificity Compared To Prostate-Specific Antigen Test

July 07, 2017

A new urine test showed significant specificity when used to detect prostate cancer, according to a new multi-institution study from researchers in Colorado, Pennsylvania, New York and Virginia. Data on the new PCA3 urine test were presented during the 105th Annual Scientific Meeting of the American Urological Association (AUA). David Crawford, MD, from the University of Colorado and Prostate Conditions Education Council, and the principal investigator on the study, states "these results will help develop a new paradigm for the early detection of prostate cancer."

This prospective, multi-practice, community-urologist based clinical trial evaluated PCA3 using 1,994 urine samples from men with elevated serum PSA (about 2.5 ng/ml) and/or an abnormal digital rectal examination (DRE). Urine samples were obtained prior to biopsy, and were processed within 48 hours of collection.

Out of the 1,994 samples, 1,946 had enough prostatic cells for PCA3 testing. After analyzing the samples, researchers determined that 816 patients (42 percent) had prostate cancer with an average Gleason score of 7. Another 219 cases (11 percent) had only high grade prostatic intraepithelial neoplasia (PIN) and/or atypical small acinar proliferation suspicious for cancer (ASAP), and 911 cases (47 percent) were benign.

The mean PCA3 value in men with prostate cancer was significantly higher than in those without cancer (50 vs. 25). The researchers concluded that PCA3 score was associated with the presence of cancer, Gleason score and cancer volume. Using a cutoff value of 35, PCA3 had an odds ratio of 3.4 for predicting prostate cancer, which is very high compared to an odds ratio of only 1.7 for PSA. PCA3 had a specificity of 78 percent and a sensitivity of 49 percent for the diagnosis of prostate cancer, while the specificity and sensitivity for serum PSA were 21 percent and 87 percent, respectively.

"This relatively new urine marker is more specific than PSA for prostate cancer detection, potentially allowing fewer unnecessary prostate biopsies in men suspected of having prostate cancer," said Christopher Amling, MD, an AUA spokesman. "If other studies confirm the association between PCA3 level, Gleason score and tumor volume, this marker may also be useful in discriminating between more and less aggressive cancers."

American Urological Association