(UroToday.com) Non-muscle-invasive bladder cancer (NMIBC) constitutes the majority of newly diagnosed bladder tumours. Scheduled frequent surveillance is indicated for NMIBC patients because of high recurrence rate and to avoid progression to muscle invasive disease. The gold standard for surveillance is flexible cystoscopy (FC). However, FC is invasive, expensive, and not always sensitive enough. The Xpert® Bladder Cancer Monitor (XBCM) is a urinary biomarker that has shown promising results as a safe replacement for FC. A previous study has shown a sensitivity of 83.3%, specificity of 75.8%, negative predictive value of 97.6%, and positive predictive value of 27.8% for high-grade NMIBC specifically. However, high-level evidence from randomised clinical trials is lacking before implementation of urinary biomarkers can be considered.
A randomised clinical non-inferiority trial is currently being conducted at four Danish urological departments. Patients with previous high-grade NMIBC (Ta, T1, and CIS) are randomised 1:1 between standard follow-up surveillance with FC versus an intervention arm with follow-up surveillance consisting of XBCM test, where FC is conducted only in case of positive test and for safety reasons every 12 months. Patients in both arms are examined every three-four months for two years. Participants were allowed to receive maintenance instillation (e.g. BCG) therapy during the trial.
As of April 2022, all 392 projected patients have been included. Nineteen recurrences have been detected in the standard arm, and 22 in the intervention arm. Risk difference of recurrence between the control arm and intervention was 1.3% (95% CI -6.6% to 9.3%) at 12 months. Thus, no difference in the detection of NMIBC is found between the two study arms. Furthermore, to detect an equal number of recurrences only 241 FCs were performed for the intervention arm, whereas 560 FCs were performed in the control group.
In summary, preliminary results indicate that XBCM is a safe alternative to cystoscopy for surveillance of NMIBC. If this is confirmed in the remaining participants, the XBCM could replace cystoscopy in most future follow-up visits in patients with previous HG NMIBC. Follow-up of all patients will be finished in April 2024 at the latest.
Presented by: Thomas Karmark Dreyer, Aarhus University Hospital, Aarhus, Denmark
Written by: Stephen B. Williams, MD, MBA, MS @SWilliams_MD on Twitter during the International Bladder Cancer Network Annual Meeting, September 28-October 1, 2022, Barcelona, Spain