Use of PCA3 in detecting prostate cancer in initial and repeat prostate biopsy patients

BACKGROUND The PCA3 urinary assay has shown promise in predicting the presence of prostate cancer. We evaluated the value of this test in patients undergoing initial and repeat prostate biopsy. METHODS PCA3 and PSA levels were obtained from 456 men with no known personal history of prostate cancer prior to prostate biopsy. Two hundred eighty-nine men underwent an initial prostate biopsy and 167 underwent a repeat prostate biopsy. PCA3 and PSA levels were compared to the prostate biopsy results. RESULTS PCA3 score was shown to be independent of prostate volume (P = 0.162) and PSA level (P = 0.959). PCA3 scores were significantly higher in patients with cancer on prostate biopsy compared to patients with negative biopsy results (P < 0.0001). In logistic regression, PCA3 showed a significantly higher AUC than PSA (0.726 vs. 0.512, P = 0.0001). This difference persisted when examining the initial biopsy subgroup, with PCA3 out-performing PSA (AUC 0.772 vs. AUC = 0.552, P < 0.0001), but not in the repeat biopsy subgroup (AUC = 0.605 vs. AUC = 0.500, P = 0.2488). CONCLUSIONS PCA3 was found to be a better predictor of prostate cancer than PSA in the total population as well as the initial biopsy population, but was not superior to PSA in the repeat biopsy population.