Surveillance patterns in non-muscle invasive bladder cancer across risk groups: a real-world analysis

OBJECTIVETo provide insight into real-world surveillance practices for patients with low risk (LR), intermediate risk (IR), and (very) high risk (HR) non-muscle invasive bladder cancer (NMIBC). MATERIALS AND METHODSCystoscopy surveillance patterns were analysed using real-world data from two population-based cohort studies in the Netherlands, comparing practices to guideline recommendations by risk group. As bladder cancer-related symptoms may prompt diagnostic investigations beyond routine follow-up, we evaluated the occurrence of such symptoms and the use of various diagnostics including cystoscopy in a subset of patients with available data. RESULTSIn total, 2,791 primary and recurrent tumours were included in the analyses. Among patients with LR NMIBC, 37.6% were monitored more intensively than recommended. The average number of cystoscopies in the first follow-up year was 1.3 (range 0-4). IR NMIBCs were generally monitored in accordance with guideline recommendations. However, adherence declined over the years following diagnosis, dropping from 78.1% to 59.3%. The proportion of IR NMIBCs who were monitored less than recommended increased from 21.7% to 39.8%. Most HR NMIBCs (88.2%) were monitored less than recommended, though adherence improved over time. In-depth analysis of 204 tumours revealed that next to cystoscopy, cytology was frequently employed, increasing with risk group (LR: 50.0%, IR: 52.3%, HR: 88.9%). Imaging (25%-65%) and biopsies (25%-85%) were also commonly performed. Surveillance patterns varied especially among IR NMIBCs. Symptoms were reported in approximately one third of bladder tumours during follow-up, but did not appear to affect surveillance patterns. CONCLUSIONOur findings demonstrate substantial deviations from recommended NMIBC surveillance practices. Cystoscopy was overused in a considerable proportion of LR NMIBC and underused in most HR cases. Surveillance of IR NMIBCs was particularly heterogenous with considerable variation in diagnostic investigations. These insights highlight opportunities to refine NMIBC surveillance schedules, aiming to improve patient outcomes and optimize allocation of healthcare resources.