Clinical performance of Xpert Bladder Cancer (BC) Monitor, a mRNA-based urine test, in active surveillance (AS) patients with recurrent non-muscle-invasive bladder cancer (NMIBC): results from the Bladder Cancer Italian Active Surveillance (BIAS) project

PurposeTo investigate the clinical performance of a new mRNA-based urine test, aiming to avoid unnecessary follow-up cystoscopy in patients under active surveillance (AS) for recurrent NMIBC.MethodsThis is a prospective cohort study enrolling patients with history of low-grade (LG) NMIBC, who developed a recurrence during the follow-up and underwent AS. Their urinary samples were analyzed by Xpert BC Monitor (Cepheid, Sunnyvale, CA, USA). The primary endpoint was to investigate if Xpert BC Monitor could avoid unnecessary cystoscopy during the follow-up period. Its sensitivity, specificity, PPVs and NPVs were calculated. A cutoff of 0.4 "linear discriminant analysis" (LDA) was optimized for the AS setting.ResultsThe cohort consisted of 106 patients with a mean age of 729.52 and a median follow-up from AS start of 8.8 (range 0-56.5) months. No statistically significant difference was found for the mean age, smoker status, lesion size, and number of lesions with a cutoff of 0.4. Of 106 patients, 22 (20.8%) were deemed to require treatment because of cystoscopic changes in size and/or number of lesions during the follow-up period. Using a cutoff value of<0.4, 34 (33.7%) cystoscopies could be avoided due to low LDA value, missing 2/22 (9%) failures, none with high-grade (HG) NMIBC. Further research on larger population remains mandatory before its clinical use.Conclusion p id=Par Xpert BC Monitor seems to be a reliable assay, which might avoid unnecessary cystoscopies without missing HG NMIBC when its cutoff is optimized for the AS setting.