Analysing cause of death during follow-up for non-muscle-invasive bladder cancer: is there a role for watchful waiting?

Abstract

Non-muscle-invasive bladder cancer (NMIBC) patients often require multiple invasive procedures during follow-up. Surveillance guidelines do not adjust for increasing frailty or competing comorbidity. We aim to evaluate the influence of these factors on the natural history of NMIBC and whether this may have implications for appropriate follow-up schedules. NMIBC patients who died in a 3-year period while on cystoscopic surveillance were identified. Frailty was assessed using the Rockwood Clinical Frailty Scale (CFS): 1-3, no frailty; 4, vulnerable; 5-9, mild/severe frailty. Similarly, three-tier categorisations were performed for comorbidity (Charlson Comorbidity Index) and for anaesthetic risk (American Society of Anesthesiologists' [ASA] score). Of the 69 patients, 26 were categorised as no frailty, 20 as vulnerable and 13 as frail. There was no difference in the proportions of those with higher risk NMIBC between the categories. Increasing frailty was associated with reduced overall survival (median 59, 29 and 13 months; p < 0.05) but not recurrence-free survival (p = 0.98) or progression-free survival (p = 0.58). Similar results were obtained using the Charlson Comorbidity Index or ASA score. No frail patients with low/intermediate-risk NMIBC had clinically significant disease progression prior to death. Frail patients with CFS ≥ 4 were found to have similar complications due to bladder cancer itself (p = 0.48) yet almost three times as many complications following cystoscopic procedures during follow-up (p < 0.05). For frail patients with low risk of progression, protocol-driven cystoscopic surveillance may not improve survival and watchful waiting may be more appropriate. Further investigation is required to determine the feasibility of this approach.