An mRNA-based assay for surveillance of patients with bladder cancer outperformed standard urine tests on certain measures in a validation study, investigators report.
The mRNA-based urine test (Xpert, Cepheid) had better sensitivity and negative predictive value compared to urine cytology and to UroVysion fluorescence in situ hybridization (FISH) testing, according to F. Johannes P. van Valenberg, of Radboud University Medical Center, Nijmegen, the Netherlands, and his colleagues.
The reported results suggest this mRNA test could partially replace white-light cystoscopy, helping urologists maintain the recommended follow-up schedules for patients with a history of bladder cancer, Dr. van Valenberg and his coauthors wrote. The report is in.
“If used in the follow-up of non–muscle invasive bladder cancer, a cystoscopy might be waived if the Xpert result is negative,” they wrote.
The negative predictive value for high-grade disease was 98%, suggesting the mRNA-based test could help urologists avoid invasive cystoscopies for intermediate- to high-risk patients, which could reduce costs and patient discomfort, they added.
The prospective, 19-center validation study enrolled 363 individuals with a history of non–muscle invasive bladder cancer who were scheduled for a standard cystoscopy. Voided urine specimens from a total of 259 patients were evaluated with all three methods: the mRNA test, FISH testing, and cytology.
In a comparison of the tests, the mRNA test identified more recurrent cancers correctly, and was more sensitive in detecting low-grade tumors than was FISH (P less than .001) or cytology (P = .021), they reported.
The mRNA test was more sensitive for detection of the most common recurrent tumors, independent of grade.
The sensitivity, specificity, and negative predictive values for mRNA testing were 74%, 80%, and 93%, respectively. By comparison the sensitivity, specificity, and negative predictive values were 51%, 80%, and 88% for FISH and 30%, 90%, and 86% for cytology.
Looking at high-grade disease only, the sensitivity, specificity, and negative predictive values were 83.3%, 75.8%, and 97.6% for mRNA testing, 75.0%, 79.5%, and 96.6% for FISH testing, and 50.0%, 90.7%, and 94.2% for cytology.
Bacillus Calmette-Guérin treatment in the past 90 days did not influence results of the mRNA test, one additional analysis showed.
The Xpert mRNA assay evaluates five mRNA targets: ABL1, ANXA10, UPK1B, CRH, and IGF2, results of which are combined to classify samples as either negative or positive. The test has a “hands-on time” of less than 2 minutes and provides results in 90 minutes, according to Dr. van Valenberg and his coinvestigators.
“Cytology requires a review by a pathologist, is not performed on the same day as a clinic visit, and has associated inter- and intraobserver variability,” the researchers wrote.
Dr. van Valenberg reported no financial disclosures related to the study. Several study coauthors reported employment or financial disclosures related to Cepheid, which provided funding and support for the conduct of the study. Study coauthors provided additional disclosures related to MDxHealth, PHotocure, Bristol-Myers Squibb, Johnson & Johnson, Roche, Bayer, and Astellas, among others.
SOURCE: van Valenberg FJP et al. Eur Urol. 2018 Dec 12. .