Clinical Outcomes of Bladder-sparing Management Versus Early Radical Cystectomy in cT1 Micropapillary Bladder Cancer: A Systematic Review and Meta-analysis.

Abstract

Background: Clinical T1 micropapillary urothelial carcinoma of the bladder is an aggressive variant histology for which early radical cystectomy (RC) is commonly recommended. However, there remain conflicting data on whether conditions in carefully selected patients may be managed with initial bladder-sparing approaches without compromising oncologic outcomes.

Objective: The objective is to systematically review and synthesize the available literature comparing bladder-sparing approaches, such as Bacillus Calmette-Guerin (BCG) therapy, and early RC outcomes in clinical stage 1 primary tumor (cT1) micropapillary carcinoma of the bladder.

Design, setting, and participants: A systematic search was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement and Cochrane Handbook for Systematic Reviews of Interventions.

Outcome measurement and statistical analysis: The primary end points were overall survival (OS) and cancer-specific survival (CSS). The included articles were descriptively assessed and time-to-event analysis was performed for select endpoints.

Results and limitations: Among 461 identified reports, nine retrospective studies met the criteria for quantitative analysis, encompassing 9402 patients of whom 9287 (99%) had non-muscle-invasive bladder cancer (NMIBC) and 1033 (11%) had a micropapillary subtype. A total of 625 patients (62%) underwent bladder-sparing approaches, whereas 392 (39%) underwent early RC. Of the bladder-sparing approaches, 88% of patients received intravesical BCG therapy. For a bladder-sparing approach for cT1 disease with a micropapillary component, pooled unadjusted hazard ratios were not statistically significant for CSS (hazard ratio [HR] 1.32, 95% confidence interval [CI] 0.60-2.88, p = 0.5) and OS (HR 0.85, 95% CI 0.68-1.07, p = 0.16) compared with early RC. Data evaluating bladder-sparing strategies beyond BCG were limited.

Conclusions: NMIBC with micropapillary features is an aggressive disease conventionally managed with early RC. In retrospective cohorts of selected patients with micropapillary cT1, available unadjusted data did not provide clear evidence of statistically significant differences in CSS or OS between initial bladder-sparing approaches and early RC.