PCA3 Materials & News

Aubin SMJ, Reid J, Sarno MJ, Blase A, Aussie J, Rittenhouse H, Rittmaster RS, Andriole GL, Groskopf J. Urology 2011;78:380-5

• This analysis of REDUCE (REduction by DUtasteride of prostate Cancer Events) trial, including men with a prostate specific antigen (PSA) 2.5-10 ng/mL and a negative baseline biopsy, showed that the value of the PCA3 Score is not affected by dutasteride treatment and that the PCA3 Assay can be used to predict repeat biopsy outcome in men taking dutasteride 
• The REDUCE  trial was a 4-year randomised, double-blind, placebo-controlled trial evaluating the effect of dutasteride on the risk of prostate cancer (PCa) in men with a PSA level of 2.5-10 ng/mL and a negative baseline biopsy (6-12 cores). At 2 and 4 years, 10-core biopsies were performed. PCA3 Scores were assessed before the year 2 and 4 biopsies in 930 men treated with dutasteride and 1,072 men treated with placebo
• Median PCA3 Scores at 2 and 4 years were similar in the placebo- and dutasteride groups, while the median serum PSA level was statistically significantly less in the dutasteride group (reduction > 50%) compared to placebo group (Figure)
• The performance characteristics (i.e. the area under the receiver operating characteristic curves [AUC ROC]) of PCA3 were similar in the placebo and dutasteride groups, independent of PCA3 Score cut-off. This demonstrates that PCA3 maintains its predictive power for biopsy-detectable PCa in men treated with dutasteride
• At year 4, PCA3 statistically significantly predicted biopsy outcome (AUC ROC 0.628; 95% confidence interval 0.556-0.700) while total PSA did not (AUC ROC 0.556; 95% confidence interval 0.469-0.642)
• A multivariate model predicting biopsy outcome at year 2, including serum PSA, prostate volume, age and family history of PCa and PCA3, had an AUC ROC of 0.712. Removing PCA3 from the model resulted in a significant decrease in diagnostic accuracy (AUC ROC 0.660; P=0.017)
• It was concluded that PCA3 can be used to predict repeat biopsy outcome in men treated with dutasteride. No adjustment in PCA3 Score was needed to yield equivalent clinical and diagnostic performance between the dutasteride and placebo groups. In dutasteride-treated men, PCA3 had a higher diagnostic accuracy for predicting repeat biopsy outcome than serum PSA. The diagnostic accuracy was further improved when PCA3 was combined with other risk factors for PCa in a multivariate model predicting biopsy outcome

Figure. Median PCA3 Scores at 2 and 4 years were similar in the placebo- and dutasteride groups, while the median serum PSA level was statistically significantly less in the dutasteride group compared to the placebo group

More information: Article at PubMed