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Sub-category:
Prostate Cancer: Early/Localized disease, Locally Advanced/Recurrent/Advanced disease, and Biology
Category:
Prostate Cancer: Early/Localized disease, Locally Advanced/Recurrent/Advanced disease, and Biology
Meeting:
2010 Genitourinary Cancers Symposium
Session Type and Session Title:
Oral Abstract Session A: Prostate Cancer
Reception and General Poster Session B: Prostate Cancer
Abstract No:
5
Author(s):
J. Groskopf, S. M. Aubin, J. Reid, M. J. Sarno, A. Blase, J. Aussie, H. Rittenhouse, G. L. Andriole, R. S. Rittmaster; Gen-Probe, Inc., San Diego, CA; Barnes-Jewish Hospital, Washington University School of Medicine, St. Louis, MO; GlaxoSmithKline, Research Triangle Park, NC
Abstract:
Background: The PCA3 molecular urine test has demonstrated utility for predicting prostate biopsy outcome in multiple studies. We assessed PCA3 clinical performance in the placebo arm of the dutasteride REDUCE Trial; this represents the largest repeat biopsy cohort evaluated to date. Methods: REDUCE was a 4-year prostate cancer risk reduction study, in which men with a negative baseline biopsy and serum PSA (sPSA) 2.5-10 were randomized to dutasteride or placebo (plac), and 10-core biopsies were obtained after 2 (yr2) and 4 years (yr4). PCA3 Scores were determined on urine specimens (n = 1140) collected from men in the plac arm who were scheduled for biopsy at y2 and/or y4. The last PCA3 Score available for each subject was correlated with biopsy outcome. Multivariate logistic regression (LR) was also performed using PCA3, sPSA, % free PSA (fPSA), prostate volume, age and family history. Results: For the urine specimens tested, 1,072/1,140 (94%) yielded sufficient RNA for PCA3 analysis; 18% of these 1072 subjects were biopsy positive for CaP. PCA3 was associated with positive biopsy rate (p < 0.0001): 6% CaP for PCA3 < 5, 57% CaP for PCA3 > 100. PCA3 AUC of 0.693 was greater than sPSA (0.612, p = 0.008 vs. PCA3) or fPSA (0.637, p = 0.065). The LR model yielded an AUC of 0.753 (p = 0.0025 vs. PCA3 alone). PCA3 was significantly correlated with biopsy Gleason Score (GS ≥ 7 vs. < 7, p = 0.0017). PCA3 determined at y2 was a significant predictor of y4 biopsy outcome (AUC = 0.634, P=0.0002); sPSA and fPSA were not predictive (p = 0.328 and 0.678, respectively). Conclusions: PCA3 clinical utility for predicting repeat biopsy outcome was confirmed in a multicenter worldwide clinical trial. Assay informative rates were similar to previously published studies. PCA3 outperformed sPSA, and a predictive model incorporating sPSA, fPSA and other clinical information significantly increased diagnostic accuracy. PCA3 correlated with biopsy GS, providing further evidence that PCA3 might be useful for identifying more aggressive CaP. Finally, PCA3 may be detecting undiagnosed cancers, as we found that PCA3 Scores measured from biopsy negative men at year 2 of the trial predicted biopsy outcome at year 4.
Faculty Disclosures
Abstract Disclosures
Abstracts that were granted an exception in accordance with ASCO's Conflict of Interest Policy
and are designated with a caret symbol (^) here and in the print version.
 Associated Presentation(s):
Other Abstracts in this Sub-Category:
Abstracts by J. Groskopf:
Presentations by J. Groskopf:
Educational Book Manuscripts by J. Groskopf:
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