Background & objective: Clinically, molecular prognostic markers for bladder carcinoma are still rare. Recently, up-regulation of clusterin protein has been suggested to relate with development and prognosis of several human cancers, but its relation with bladder cancer is unclear. This study was to analyze correlation of expression of clusterin protein to clinicopathologic parameters and prognosis of bladder cancer with tissue chip.
Methods: A tissue microarray containing 81 cases of bladder carcinoma was constructed. The expression of clusterin was detected by immunohistochemistry; its correlation with clinicophathologic parameters was analyzed.
Results: Of the 81 cases of bladder cancer, 69 were detectable by immunohistochemistry, 32 (46.4%) of which showed overexpression of clusterin protein. Overexpression rate of clusterin was significantly higher in poorly differentiated (G3 grade) tumors than in well differentiated (G1-G2 grades) tumors (75.0% vs. 34.7%, P=0.002), and was significantly higher in invasive (T2-T4 stages) tumors than in superficial (Ta-T1 stages) tumors (65.4% vs. 34.9%, P=0.014). Expression of clusterin was negatively correlated with prognosis of bladder cancer patients (log-rank=5.88, P=0.015); the recurrence-free survival time of patients with overexpression of clusterin was shorter than that of patients with normal expression of clusterin (37.3 months vs. 48.8 months).
Conclusion: The overexpression of clusterin might be a molecular prognostic marker of bladder cancer.