Prognostic impact of percentage of squamous differentiation in patients with nonbilharzial squamous cell carcinoma and transitional cell carcinoma treated with radical cystectomy.

498Background: Squamous differentiation has been reported to occur in 10-22 % of transitional cell carcinoma. The prognostic impact of squamous differentiation is controversial. In addition, it remains unclear whether the percentage of squamous differentiation impact outcome of patients with nonbilharzial squamous cell carcinoma and transitional cell carcinoma treated with radical cystectomy Methods: We performed a retrospective study of patients with non-bilharzial squamous variants or squamous bladder carcinoma treated in two French institutions. The percentage of squamous differentiation was determined by an expert GU pathologist on radical cystectomy specimens. Progression-free survival (PFS) and cancer-specific survival (CSS) were analyzed according to the percent of squamous differentiation. Survivals were estimated using the Kaplan-Meier method and compared using multivariate Cox proportional hazard regression analysis. Results: Forty patients were identified including 28 and 12 patients which tumo...