Expression and prognostic value of CD44 isoforms in transitional cell carcinoma of renal pelvis and ureter

Purpose: We retrospectively evaluated the expression and prognostic value of CD44 isoforms in transitional cell carcinoma of the renal pelvis and ureter. Materials and Methods: Using a labeled streptavidin-biotin-peroxidase method we performed immunohistochemical staining of archival tissue specimens from 62 men and 26 women with a mean age of 66.5 years who had transitional cell carcinoma of the renal pelvis and ureter. Results: The expression of CD44 standard (CD44s) and splice variant 6 (CD44v6) proteins was significantly decreased in relation to histological grade and pathological stage, while expression of the CD44 splice variant 3 (CD44v3) protein was decreased in relation to histological grade. The prognosis was more favorable in patients with greater versus less than 25% CD44s positive cells. CD44v3 and CD44v6 proteins had no prognostic value. Multivariate analysis indicated that only pathological stage has an independent prognostic value. Conclusions: The expression of CD44 isoforms is closely associated with tumor differentiation and progression. However, it is not an independent marker and has no statistical significance greater than that of stage.