Haese A et al. (2008) Clinical utility of the PCA3 urine assay in European men scheduled for repeat biopsy. Eur Urol 54: 1081–1088

An American study has shown that, at repeat biopsy, detection of prostate cancer antigen 3 (PCA3), which is highly expressed in over 95% of malignant prostate tissue, is superior to PSA measurements in the detection of prostate cancer. In light of these findings, Haese et al. conducted a prospective, multinational, multicenter European study to asses the clinical utility and performance of the PCA3 assay.

Data were assessed from 463 men with 1–2 previous negative prostate biopsies who were scheduled for repeat biopsy, which detected prostate cancer in 128 (28%) men. Increasing PCA3 score corresponded with an increased risk of positive repeat biopsy; mean scores were higher in men with a positive biopsy than in men with a negative biopsy (63.8 vs 35.5). The PCA3 score cut-off of 35 provided optimal specificity (72%) and sensitivity (47%), and had a greater diagnostic accuracy than the percentage of free PSA (cut-off of 25%, specificity 23%).

Increasing PCA3 scores were associated with increasing clinical stage and aggressiveness of prostate cancer, as well as with incidence of high-grade prostate intraepithelial neoplasia, the authors noted. They added that PCA3 score cut-off values could also be used to reduce unnecessary biopsies while keeping the risk of missing cancers low, although further evaluation is needed to confirm this suggestion.

Haese and colleagues conclude that using the PCA3 score together with other diagnostic variables can help to identify patients likely to require a repeat biopsy.