Clinical Outcomes of Patients With Histologic Variants of Urothelial Carcinoma Treated With Selective Tetramodal Bladder-preservation Therapy Incorporating Consolidative Partial Cystectomy.

Abstract

Tetramodal bladder-preservation therapy includes maximal transurethral resection (TUR), induction chemoradiotherapy (CRT), and consolidative partial cystectomy with pelvic lymph node dissection. Tetramodal bladder-preservation therapy theoretically provides surgical consolidation of chemotherapy- and radioresistant cells. However, its efficacy in providing optimal cancer control for patients with histologic variants of urothelial carcinoma (VUCs) is currently unknown. We compared the oncologic outcomes between patients with muscle-invasive bladder cancer (MIBC) and pure urothelial carcinoma (PUC) and those with MIBC and VUCs after selective tetramodal bladder-preservation therapy. We prospectively enrolled 154 patients. After maximal TUR and induction CRT, patients with a clinical complete response were offered consolidative partial cystectomy to achieve bladder preservation, with radical cystectomy recommended for the others. The VUCs identified in the maximal TUR samples were categorized according to the 2004 World Health Organization classification. The primary endpoint was cancer-specific survival. The secondary endpoints included the clinical and pathologic response rates to induction CRT and MIBC recurrence-free survival. A VUC was identified in 37 patients (24%). The most frequent variants involved glandular differentiation (n= 13), squamous differentiation (n= 11), and micropapillary (n= 8). No difference was found in the clinical complete response rate to CRT between PUC and VUCs (P= .81). On an intention-to-treat basis, the 5-year cancer-specific survival rates for those with PUC (n= 116) and VUC (n= 37) were 82% and 81% (P= .86), respectively. Tetramodal bladder-preservation therapy incorporating partial cystectomy could provide favorable locoregional control and survival for patients with VUC. Thus, patients with MIBC need not be excluded from the bladder-preservation approach because of the presence of a variant histologic type.