Clusterin as a diagnostic and prognostic marker for transitional cell carcinoma of the bladder

We investigated the feasibility of profiling and measuring the concentration of clusterin in urine and serum for individuals with transitional cell carcinoma (TCC) of the bladder and comparing it with nontumor controls. In addition, we analyzed the correlation of expression of clusterin in specimens of TCC to various clinicopathologic parameters and prognosis of bladder cancer. Blood and urine samples were used from 68 patients with TCC of the bladder and from 61 patients with benign urological diseases. Enzyme-linked immunosorbent assays (ELISA) were performed for clusterin from serum and urine. Quantitation of clusterin mRNA was carried out in 68 bladder tumor specimens from radical cystectomy or transurethral resection and 26 normal bladder specimens from BPH patients by using RT-PCR method. Correlation for the expression of clusterin mRNA with clinicopathologic parameters was analyzed. Serum and urine clusterin was significantly higher in individuals with bladder cancer than control (p = 0.001). Sensitivity and specificity of serum and urine clusterin as a tumor marker for TCC of the bladder was found to be 80%, 91%, 87.1% and 96.7% respectively. Clusterin expression was significantly higher in TCC specimens than normal tissue specimens (P < 0.001). Expression of clusterin was significantly higher in patients with invasive TCC of the bladder than that in patients with superficial TCC and control (P < 0.001). Overexpression of clusterin mRNA was significantly associated with tumor recurrence and overall survival (p < 0.001). The recurrence-free survival time of patients with overexpression of clusterin was significantly shorter than that of patients with weak expression of clusterin (9.8 months vs. 35.2 months). Clusterin may be considered as a potential diagnostic and prognostic biomarker for bladder cancer using urine, serum and/or molecular biology techniques.