1924 ANALYSIS OF A CIRCULATING MICROVESICLE-BASED ASSAY IN AT-RISK PATIENTS FOR THE DETECTION OF PROSTATE CANCER

Abstract

You have accessJournal of UrologyProstate Cancer: Detection and Screening1 Apr 20111924 ANALYSIS OF A CIRCULATING MICROVESICLE-BASED ASSAY IN AT-RISK PATIENTS FOR THE DETECTION OF PROSTATE CANCER Adam Kibel, Gerald Andriole, Daniel Lin, Robert Vessella, Steven Stratton, Mitchell Sokoloff, David Spetzler, and Christine Kuslich Adam KibelAdam Kibel St. Louis, MO More articles by this author , Gerald AndrioleGerald Andriole St. Louis, MO More articles by this author , Daniel LinDaniel Lin Seattle, WA More articles by this author , Robert VessellaRobert Vessella Seattle, WA More articles by this author , Steven StrattonSteven Stratton Tucson, AZ More articles by this author , Mitchell SokoloffMitchell Sokoloff Tucson, AZ More articles by this author , David SpetzlerDavid Spetzler Phoenix, AZ More articles by this author , and Christine KuslichChristine Kuslich Phoenix, AZ More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.2062AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES While PSA-based testing has improved the ability to detect prostate cancer (PCa), it is limited by low sensitivity and specificity. Circulating microvesicles (cMV) are membrane-bound structures in the blood that carry material from their cell of origin. PCa patients have cMV with biosignatures that correlate with the presence of disease. The aim of this study was to evaluate a novel cMV-based assay, Carisome Prostate MDx 1.0, for the detection of PCa. METHODS The assay was developed by selecting antibodies to protein biomarkers based on their ability to differentiate between men with and without PCa. Sensitivity and specificity were evaluated using retrospective frozen plasma samples from men with biopsy-confirmed, nonmetastatic PCa (n=346) and controls (n=269). Prostate-specific cMV were captured and analyzed. Samples were blindly classified as positive, negative, or borderline according to median fluorescence intensity (MFI) values acquired by a flow-based technology. RESULTS The assay was successfully run on 615 of 736 (84%) cases and controls. Pre-analytic sample collection conditions (eg, centrifugation, temperature) resulted in 100 samples having anomalously high MFI, and there were no results for the remaining 21. The overall sensitivity, specificity, and Receiver Operating Characteristic (ROC) curve area under the curve (AUC) in the validation cohort were 82%, 88%, and 0.92, respectively. In a subset of samples with known PSA values (n=346), the assay performed better than PSA. It also had higher performance in a high-risk subset. CONCLUSIONS Carisome Prostate MDx 1.0 is a promising new assay for the detection of PCa, with performance characteristics superior to serum PSA. While further validation in larger cohorts is needed, this assay could significantly improve PCa screening, thus enabling physicians to make more informed decisions regarding invasive testing and therapies. Performance of the Carisome Prostate MDx 1.0 on Different Cohorts of Men Broken up by PSA All samples with corresponding PSA values (n=346) PSA ranging from 0 to 4 ng/mL (n=173) PSA > 4 ng/mL (n=173) Sensitivity 89% Sensitivity 84% Sensitivity 91% Specificity 85% Specificity 85% Specificity 85% Accuracy 87% Accuracy 85% Accuracy 88% AUC=0.92 AUC=0.80 AUC=0.93 © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e769-e770 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Adam Kibel St. Louis, MO More articles by this author Gerald Andriole St. Louis, MO More articles by this author Daniel Lin Seattle, WA More articles by this author Robert Vessella Seattle, WA More articles by this author Steven Stratton Tucson, AZ More articles by this author Mitchell Sokoloff Tucson, AZ More articles by this author David Spetzler Phoenix, AZ More articles by this author Christine Kuslich Phoenix, AZ More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...