An advanced noninvasive molecular diagnostic test for detecting recurrent urothelial carcinoma (Cxbladder Monitor) demonstrated high sensitivity and a high negative predictive value (NPV) in a recently published prospective study.
Its performance was investigated using 1,036 urine samples prospectively collected from 763 patients undergoing routine surveillance. The analyses showed that the test had 93% sensitivity and a 97% NPV (J Urol [epub ahead of print] Dec. 14, 2016).
Findings of another study accepted for publication in Urologic Oncology showed that the quantitative, objective test outperformed cytology and all other comparator FDA-approved urine-based tests for ruling out recurrent urothelial carcinoma (UC).
Yair Lotan, MD, of UT Southwestern Medical Center in Dallas, is the senior author of the Journal of Urology paper and first author of the Urologic Oncology paper. He told Urology Times, “The Cxbladder Monitor test was designed to serve as a ‘rule-out’ test to maximize sensitivity. The advantage of such a test is that it rarely misses cancer, and it does much better than other tests such as cytology and NMP22 for detecting low-grade tumors. The disadvantage is that a ‘positive’ test is frequently not associated with cancer.
“Physicians should be aware that because the positive predictive value of Cxbladder Monitor is low, a positive test should not provoke a high level of anxiety,” he said.
“The clinical utility of a diagnostic tool depends on it having both high sensitivity and high NPV,” said David Darling, a co-author on both studies and chief executive officer of Pacific Edge Ltd., the maker of the test. “The study published in the Journal of Urology is the first peer-reviewed clinical evaluation of Cxbladder Monitor, and the results show that the test provides clinically meaningful results.
“Based on the performance of Cxbladder Monitor, we believe it could be used as the preferred adjunct to cystoscopy in surveillance of patients for recurrent UC, replacing other urine-based tests. In addition, as a confirmatory negative adjunct to cystoscopy, Cxbladder Monitor could reduce the need for additional investigations. Furthermore, it may also be considered as a monitoring tool for patients who may not tolerate cystoscopy for medical or religious reasons,” Darling said.
Cxbladder Monitor uses an algorithm that combines patient clinical characteristics with measurement of gene expression from urothelial cells in urine. Via RT-qPCR, it quantifies mRNA expression of five genetic biomarkers that were previously clinically validated in a test for initial diagnosis of urothelial carcinoma (Cxbladder Detect) in patients with hematuria.