Urine PCA3 Superior to PSA in Predicting Prostate Cancer
SAN FRANCISCO—Urine levels of prostate cancer gene 3 (PCA3) can more specifically predict the presence of prostate cancer than PSA levels, according to new findings.
E. David Crawford, MD, of the University of Colorado Health Sciences Center in Denver, and collaborators studied 1,994 men with elevated serum PSA (greater than 2.5 ng/mL) and/or abnormal digital rectal examination (DRE) findings. Subjects provided urine specimens prior to a routine minimum 10-core prostate biopsy. Urine samples were processed within 48 hours of collection.
Of the 1,994 urine specimens, 1,946 had enough prostatic cells for PCA3 testing. Prostate cancer was diagnosed in 816 (42%) of the 1,946 patients. They had a mean Gleason score of 7 (range 6-10). The mean PCA3 value in men with prostate cancer was significantly higher than in those without cancer (50 vs. 25).
A PCA3 value above 35 was more strongly associated with the presence of prostate cancer than an elevated PSA level (3.4 times increased odds vs. 70% increased odds), Dr. Crawford's team reported at the American Urological Association annual meeting. PCA3 had a sensitivity and specificity of 49% and 78%, respectively, for the diagnosis of prostate cancer; serum PSA had a sensitivity and specificity of 87% and 21%, respectively.
Moreover, higher PCA3 scores were associated with higher Gleason scores and greater cancer volume.
“Screening for prostate cancer is evolving into a three-legged stool of PSA-DRE-PCA-3,” said Dr. Crawford, Professor of Surgery and Head of the Section of Urologic Oncology.