Impact of Histologic Variants of Bladder Cancer on Oncology Outcome After Radical Cystectomy

Abstract

Purpose: To evaluate the oncological outcome of histologic variants in bladder cancer patients who underwent radical cystectomy. Materials and Methods: We identified 393 bladder cancer patients who underwent radical cystectomy at single center between January 2007 and August 2014. Patients were divided into 4 groups according to histologic types: pure urothelial cell carcinoma (UC) and squamous, micropapillary, and other variants. Kaplan-Meier analysis was performed to assess recurrence-free (RFS) and overall survivals (OS). The patients were divided into those with pathologic stage and nodal status. Results: Among 393 bladder cancer patients, squamous, micropapillary histologic variants were observed in 38 (9.7%), 26 (6.6%), respectively, whereas 39 had other variant types. Stage T3 cancer occurred in more patients with histologic variant compared with those with pure UC. Pathologic positive nodal status was also frequently found in the histologic variant groups. Subgroup analysis according to T stage and nodal status showed no significant difference in RFS and OS. On multivariate analysis, pathologic T stage (stage T2: hazard ratio [HR], 2.75; 95% confidence interval [CI], 1.34–5.63; p=0.005; stage ≥T3: HR, 3.20; 95% CI, 1.62–6.30; p=0.001) and nodal status (HR, 1.85; 95% CI, 1.05–2.56; p=0.028) were prognostic factors for RFS. Conclusions: In patients who underwent radical cystectomy, histologic variants were detected more often at advanced pathologic stage. Although histologic variants have been identified in the radical cystectomy specimen, treatment should be performed according to the pathologic stage.