Nonprimary pT1 nonmuscle invasive bladder cancer treated with bacillus Calmette-Guerin is associated with higher risk of progression compared to primary T1 tumors

Abstract

Purpose: Few studies have examined the prognostic significance of prior tumor resection(s) in cases of T1 nonmuscle invasive bladder cancer treated with intravesical bacillus Calmette-Guerin. We examined this issue by comparing the prognosis of primary vs nonprimary T1 nonmuscle invasive bladder cancer treated with bacillus Calmette-Guerin.

Materials and methods: Patients with pT1 nonmuscle invasive bladder cancer treated with bacillus Calmette-Guerin were identified and tumor pathology was reviewed. Patients were then stratified into primary vs nonprimary tumors, and outcomes were compared using univariate, multivariate and Kaplan-Meier survival analyses, and the Cox regression model adjusting for various clinical and pathological features including, age, gender, tumor size, multifocality, pathological grade and associated carcinoma in situ.

Results: The study included 191 patients, 95 (49.7%) with primary and 96 (50.3%) with nonprimary tumors. The clinical and pathological characteristics were comparable. For the primary vs the nonprimary group progression rates were 24.2% vs 39.6%, respectively (HR 2.07, 95% CI 0.98-3.71, multivariate p = 0.03) and the 5-year progression-free survival rates were 71.9% vs 51.5%, respectively (log rank p <0.001). This difference remained significant on multivariate Cox regression analysis (HR 2.53, 95% CI 1.40-4.57, p = 0.002). There was no difference between the groups in recurrence or disease specific mortality.

Conclusions: Nonprimary T1 nonmuscle invasive bladder tumors treated with bacillus Calmette-Guerin carry a significantly higher risk of progression to muscle invasive disease compared to primary tumors. This information may be used in combination with other prognostic factors to identify those at high risk for progression when counseling patients.