The influence of variant histology on survival outcomes of radical cystectomy for bladder cancer.

Abstract

278 Background: The role of variant histology bladder cancer as an independent prognostic factor for survival after radical cystectomy is poorly defined. Our aim was to examine the impact of variant histology on survival. Methods: A retrospective analysis of prospectively collected data from the University of Southern California Bladder Cancer Database was performed. Between 1971 and 2008, 2098 patients underwent radical cystectomy and extended pelvic lymph node dissection for primary bladder cancer. All surgical specimens underwent centralized pathologic review by dedicated genitourinary pathologists. Histologic type was categorized according to the WHO/ISUP 1998 classification as urothelial carcinoma (UC; n=1595), UC + variant (n=380), or non-urothelial carcinoma (Non-UC; n=123). 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 12.8 years (range, 0 to 36.6 years). The predicted 5-year OS (61%, 53%, and 47%, Log rank p=0.005) and RFS (68%, 59%, and 58%, Log rank p=0.001) rates differed between patients with UC, UC + variant, and Non-UC histology. Multivariable analysis showed that Non-UC (but not UC + variant) histology was independently associated with OS (Non-UC versus UC: HR 1.26, 95% CI 1.01 to 1.57, p=0.040; UC + variant versus UC: HR 0.97, 95% CI 0.85 to 1.12, p=0.697) but not RFS (Non-UC versus UC: HR 1.14, 95% CI 0.83 to 1.56, p=0.411; UC + variant versus UC: HR 1.06, 95% CI 0.88 to 1.28, p=0.551). Conclusions: Non-UC histology was independently associated with poorer OS after radical cystectomy for bladder cancer. Clinical trials are needed to determine whether this high risk group will benefit from multimodal therapy.