Objective:The primary objective of this study is to determine the performance characteristics and clinical utility of the PCA3 assay in detecting pCA at repeat biopsy.
Patients and methods:78 patients with history of one or more negative TRUS prostatic biopsy result were enrolled in the study. All scheduled for repeat biopsy. The data of the patients with positive biopsy results were compared with negative ones. Evaluation of the diagnostic accuracy and efficiency of two different cut-off of PCA3 score (20 and 35) as an indication for repeat biopsy was carried out.
Results:The mean age was 66.1 ± 3.9 years, the mean prostate volume was 66.5 ± 19.4 gram, 51.3% had one negative previous biopsy, and 48.7% had two previous biopsies, their mean PSA was 18.2 ± 8.1 ng/ml, and mean PCA3 scores was 36.3 ± 21.5.The mean PCA3 score was statistically significant higher in the patients with positive results than those with negative results (54.2 ± 26.8 vs. 54.2 ± 26.8, P=.0.001).As regard score of 35 as PCA3 cut-off, the was statistically significant higher percent of patients with PCA3 scores more than 35 in the patients with positive result than with negative results (68.2% vs.31.8%, respectively, P=0.02). Sensitivity, specificity, PPV and NPV of PCA3 score cut-off of 20 vs 35 were 90.9 vs 63.4%, 27.8 vs 83.9%, 43.5 vs 60.9% and 83.4 vs 85.5%, respectively.
Conclusions:PCA3 remained a good predictor of prostate cancer in patients scheduled for repeat biopsy, and could prevent unnecessary prostate biopsies if the value is low.