Surveillance Intensity in Intermediate Risk, Nonmuscle Invasive Bladder Cancer: Revisiting the Optimal Timing and Frequency of Cystoscopy.

PURPOSE

We sought to determine the optimal cystoscopic interval for intermediate risk, nonmuscle invasive bladder cancer.

MATERIALS AND METHODS

A retrospective analysis of patients with intermediate risk, nonmuscle invasive bladder cancer (2010-2017) was performed and 3 hypothetical models of surveillance intensity were applied: model 1: high (3 months), model 2: moderate (6 months) and model 3: low intensity (12 months) over a 2-year period. We compared timing of actual detection of recurrence and progression to proposed cystoscopy timing between each model. We calculated number of avoidable cystoscopies and associated costs.

RESULTS

Of 107 patients with median followup of 37 months, 66/107 (77.6%) developed recurrence and 12/107(14.1%) had progression. Relative to model 1, there were 33 (50%) delayed detection of recurrences in model 2 and 41 (62%) in model 3. There was a 1.7-month mean delay in detection of recurrence for model 1 vs 3.2, and a 7.6-month delay for models 2 and 3 (p <0.001 model 1 vs 2; p <0.001 model 2 vs 3). Relative to model 1, there were 8 (67%) and 9 (75%) delayed detection of progression events in model 2 and 3. There were no progression-related bladder cancer deaths or radical cystectomies due to delayed detection. Mean number of avoidable cystoscopies was higher in model 1 (2) vs model 2 (1) and 3 (0). Model 1 had the highest aggregate cost of surveillance ($46,262.52).

CONCLUSIONS

High intensity (3-month) surveillance intervals provide faster detection of recurrences but with increased cost and more avoidable cystoscopies without clear oncologic benefit. Moderate intensity (6-month) intervals in intermediate risk, nonmuscle invasive bladder cancer allows timely detection without oncologic compromise and is less costly with fewer cystoscopies.