300 Background: The role of micropapillary urothelial carcinoma (MUC) variant histology as an independent prognostic factor for survival after radical cystectomy has not been studied. Our aim was to examine the impact of MUC on survival. Methods: A retrospective analysis of prospectively collected data from the University of Southern California (USC) Bladder Cancer Database was performed. Between 1985 and 2008, 1681 patients underwent radical cystectomy and extended pelvic lymph node dissection for primary bladder cancer. All surgical specimens underwent central pathologic review by dedicated genitourinary pathologists. Histologic type was categorized according to the WHO/ISUP 1998 classification as urothelial carcinoma (UC; n=1648) or MUC (n=33). The outcomes were overall survival (OS) and recurrence-free survival (RFS). The Kaplan-Meier method and Cox proportional regression models were used to analyze survival data. Results: The median follow-up duration was 10 years (range, 0 to 25 years). Baseline characteristics were similar between histologic types except MUC was associated with advanced clinical (cTanyN1-3: 2% versus 9%, p=0.03) and pathologic (pTanyN1-3: 23% versus 46%, p=0.01) TNM stage, multifocality (37% versus 58%, p=0.02), and high nuclear grade (84% versus 97%, p=0.04). The predicted 5-year OS (59% and 67%, Log rank p=0.79) and RFS (67% and 58%, Log rank p=0.50) rates did not differ between patients with UC and MUC. Multivariable analysis showed that histologic type was not independently associated with OS (HR 0.92, 95% CI 0.56 to 1.50, p=0.73) or RFS (HR 0.92, 95% CI 0.52 to 1.63, p=0.77). Conclusions: Outcomes of radical cystectomy for patients with MUC are similar to those with UC when controlling for other clinical and pathologic factors.
Management Trends and Outcomes of Patients Undergoing Radical Cystectomy for Urothelial Carcinoma of the Bladder: Evolution of the University of Southern California Experience over 3,347 Cases
