To evaluate the diagnostic accuracy of the Xpert Bladder Cancer (BC) Monitor, compared to cystoscopy and cytology in the oncological follow-up of non-muscle invasive bladder cancer (NMIBC).
140 patients with a previous history of NMIBC undergoing routine surveillance at our department were enrolled prospectively (ISRCTN study registry number 37210907). Urine cytology was evaluated according to the Paris classification system. In addition, urinary specimens were analyzed using the Xpert BC Monitor, which measures five target mRNAs (ABL1, CRH, IGF2, UPK1B, ANXA10) using real-time-PCR. Descriptive analysis, diagnostic accuracy including sensitivities, specificities, predictive values [positive (PPV) and negative (NPV)], receiver operating characteristic (ROC) curves, and area under the curve (AUC) were calculated.
The overall sensitivity (0.84) and NPV (0.93) of the Xpert BC Monitor were significantly superior to that of bladder washing cytology (0.33 and 0.76, p<0.001). Subgroup analyses confirmed the high sensitivity of the Xpert BC Monitor even in low-grade (0.77) and pTa (0.82) disease compared to barbotage cytology (low-grade: 0.13 and pTa: 0.21). The overall specificity of the Xpert BC Monitor and barbotage cytology was similar (0.91 vs. 0.94; p=0.41). Combining the Xpert BC Monitor with barbotage cytology (AUC=0.85) did not enhance diagnostic performance compared to the Xpert BC Monitor alone (AUC=0.87).
In this study, we report for the first time that Xpert BC Monitor, a new mRNA based urine test, outperformes cytology in regard of sensitivity and NPV, even in low-grade and pTa tumors, with no reduction of specificity. This article is protected by copyright. All rights reserved.
BJU international. 2017 Sep 20 [Epub ahead of print]
Renate Pichler, Josef Fritz, Gennadi Tulchiner, Gerald Klinglmair, Afschin Soleiman, Wolfgang Horninger, Helmut Klocker, Isabel Heidegger
Department of Urology, Medical University Innsbruck, Austria., Department of Medical Statistics, Informatics and Health Economics, Medical University Innsbruck, Austria., Clinical Pathology and Cytodiagnostics, Tyrolean State Hospitals Ltd., Innsbruck, Austria.