Expression of osteopontin and clusterin in transitional cell carcinoma of the bladder: Comparison to the pathologic stage

Purpose: This study was performed to evaluate the expressions of osteopontin (OPN) and clusterin in a transitional cell carcinoma (TCC) of the urinary bladder, and then compare their expression rates with the tumor invasiveness. Materials and methods: Twenty-five superficial and 25 invasive TCC were used for immunohistochemical staining. Results: All 25 non-invasive TCC showed a strong positive reaction for OPN. Twenty of the invasive TCC showed a strong positive reaction for OPN, but 5 showed only a weak positive reaction. OPN expression was significantly decreased in the invasive TCC (p=0.02). Eighteen superficial TCC showed a weak positive reaction for clusterin, with 7 showing a negative reaction. Nine invasive TCC showed a strong positive reaction for clusterin, and 11 showed only a weak positive reaction. Five invasive TCC showed a negative reaction for clusterin. Clusterin expression was significantly increased in the invasive TCC (p=0.001). Conclusions: These results may suggest that OPN and clusterin could be used as markers to predict the biological behavior of a TCC.