It is known that a prostate cancer gene 3 (PCA3) urine assay is superior to serum PSA level or PSA-related indices for predicting a positive biopsy result in European and US men.
This is the first report on PCA3 in a large cohort of Japanese men. The diagnostic value of the PCA3 score in Japanese men was similar to those reported in European and US men. The study concludes that a combination of PSA density and PCA3 score may be useful for selecting patients who could avoid an unnecessary biopsy.
OBJECTIVE:To examine the diagnostic performance of the prostate cancer gene 3 (PCA3) score for prostate cancer in Japanese men undergoing prostate biopsy.
PATIENTS AND METHODS: This Japanese, multicentre study included 647 Asian men who underwent extended prostate biopsy with elevated prostate-specific antigen (PSA) and/or abnormal digital rectal examination (DRE). Urine samples were collected after DRE. The PCA3 score was determined using a PROGENSA PCA3 assay and correlated with biopsy outcome. Its diagnostic accuracy was compared with that of serum PSA level, prostate volume (PV), PSA density (PSAD), and free/total PSA ratio (f/t PSA).
RESULTS: A total of 633 urine samples were successfully analysed (the informative rate was 98%). Median PSA was 7.6 ng/mL. Biopsy revealed cancer in 264 men (41.7%). The PCA3 score for men with prostate cancer was significantly higher than that for men with negative biopsies (median PCA3 score: 49 vs. 18; P < 0.001). The rate of positive biopsy was 16.0% in men with a PCA3 score of < 20 and 60.6% in those with a PCA3 score of ≥50. Using a PCA3 score threshold of 35, sensitivity and specificity were 66.5 and 71.6%, respectively. The area under the curve of the PCA3 score was significantly higher than that of the f/t PSA in men with PSA 4-10 ng/mL (0.742 vs 0.647; P < 0.05). In men with PSAD < 0.15 and PCA3 < 20, only three (4.2%) out of 72 men had prostate cancer.
CONCLUSIONS: The PCA3 score was significantly superior to f/t PSA in predicting a positive biopsy result for prostate cancer in Japanese men with PSA 4-10 ng/mL. The combination of PSAD and PCA3 score may be useful for selecting patients who could avoid an unnecessary biopsy.
Written by:
Ochiai A, Okihara K, Kamoi K, Oikawa T, Shimazui T, Murayama SI, Tomita K, Umekawa T, Uemura H, Miki T. Are you the author?
Department of Urology, Kyoto Prefectural University of Medicine, Kyoto.
Reference: BJU Int. 2013 Jan 18. Epub ahead of print.
doi: 10.1111/j.1464-410X.2012.11683.x
PubMed Abstract
PMID: 23331404
UroToday.com Prostate Cancer Section