Source: Renal + Urology News
URL: https://www.renalandurologynews.com/news/bladder-cancer-nmibc-urinary-biomarker-test-xbcm-reduces-cystoscopy/
Xpert® Bladder Cancer Monitor (XBCM) can safely replace alternating cystoscopies in high-grade NMIBC surveillance, reducing procedure burden by 56% without compromising oncologic outcomes. The 91% sensitivity and 99% negative predictive value support its use for detecting high-grade recurrences, though 2 pTa high-grade tumors were missed.
Study Design & Population
Multicenter randomized controlled trial (DaBlaCa-15, NCT04100733) enrolling 377 Danish patients with high-grade NMIBC.
- Intervention arm (n=190): XBCM + urinary cytology every 4 months + annual cystoscopy
- Control arm (n=187): Cystoscopy + urinary cytology every 4 months
- Demographics: Predominantly male (83% vs 82%) with median ages of 72.2 and 71.0 years
Key Findings
- Primary endpoint: Non-inferiority achieved with risk difference 0.08% at 24 months
- Recurrence rates: 12% intervention vs 11% control over 2 years
- Cystoscopy reduction: 455 vs 1,029 procedures (56% decrease)
- Disease progression: 2 vs 3 patients (intervention vs control)
XBCM Performance Metrics
- Sensitivity: 91%
- Specificity: 65%
- PPV: 16%
- NPV: 99%
Clinical Implications
- Oncologically safe alternative to standard cystoscopic surveillance in high-grade NMIBC
- Early detection: Identified recurrence median 8.3 months before cystoscopy in 13/22 patients
- Upper tract detection: All 4 cases diagnosed via CT after positive XBCM + negative cystoscopy
- Guideline impact: May support EAU guideline revision on urinary markers in NMIBC follow-up
Limitations
- Statistical power: Lower-than-expected recurrence rate limits safety conclusions
- Missed tumors: 2 pTa high-grade recurrences not detected by XBCM
- Study scope: Limited to single biomarker platform without comparator tests
- False positives: 16% PPV indicates high false-positive rate
