Congress abstract

Rittmaster RS, Aubin SM, Reid J, Sarno MJ, Blase A, Aussie J, Rittenhouse H, Andriole GL, Groskopf J. Presented at the American Society of Clinical Oncology (ASCO) 2010 Genitourinary Cancers Symposium, 5-7 March 2010, San Francisco, California, USA

  • This analysis of the large multicentre REDUCE trial, including men with a prostate specific antigen (PSA) 2.5-10 ng/mL, showed that 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 (REduction by DUtasteride of prostate Cancer Events) trial is a 4-year randomised, placebo-controlled trial evaluating the effect of dutasteride on the risk of prostate cancer in men with a PSA level of 2.5-10 ng/mL and a negative baseline biopsy. At baseline, 2 and 4 years, 10-core biopsies were performed and PCA3 Scores assessed in 1,308 men treated with dutasteride and 1,554 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 compared to placebo group (Figure)
  • The performance characteristics of PCA3 were similar in the placebo and dutasteride groups while this was not the case for serum PSA (Table)
  • In the dutasteride group at 4 years, PCA3 statistically significantly predicted repeat biopsy outcome (Area Under the Receiver Operating Characteristic (AUC ROC) curve: 0.627; P<0.001) while serum PSA was not predictive (AUC ROC 0.556; P=0.103)
  • Adding PCA3 to a multivariate model (including serum PSA, prostate volume, age and family history of prostate cancer) improved the prediction of biopsy outcome at year 2 and 4 in the dutasteride group
  • It was concluded that PCA3 can be used to predict repeat biopsy outcome in men treated with dutasteride. The PCA3 Score was similar in men receiving placebo or dutasteride and the performance characteristics of PCA3 were also comparable in both groups. In dutasteride-treated men, PCA3 had a higher diagnostic accuracy for predicting repeat biopsy outcome than serum PSA, and including PCA3 in a multivariate model improved its diagnostic accuracy

Median PCA3 Score and PSA level in men taking placebo or dutasteride

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

Table: The sensitivity and specificity of the PCA3 Score are comparable in the placebo and dutasteride groups while this is not the case for serum PSA

  Year 2 Year 4
  Sensitivity Specificity Sensitivity Specificity
PCA3 Score (cut-off 35)        
  • Placebo
 55% 78% 35% 78%
  • Dutasteride
 41% 81% 35% 75%
PSA (cut-off 4 ng/mL)        
  • Placebo
 83% 27% 95% 21%
  • Dutasteride
 16% 91% 19% 90%

More information: Abstract

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