Evaluation of serum and urine clusterin as a potential tumor marker for urinary bladder cancer.

Clusterin is a stress-associated cytoprotective chaperone up-regulated by various apoptotic triggers in many cancers and neurodegenerative diseases. No valid information about serum or urine clusterin concentration in patiens with bladder cancer exists. Aim of our paper was evaluation of the urine and serum clusterin concentrations in individuals with bladder cancer. Blood and urine samples were used from 43 patients with urothelial tumors of the urinary bladder and from 50 patients with benign urological diseases. Blood and urine were collected before cystoscopy. Enzyme-linked immunosorbent assays (ELISA) were performed for clusterin from serum and urine. Serum clusterin was higher in individuals with bladder cancer (means 185,812.5 vs 171,946.5 kU/l, p=0.04). Sensitivity for bladder cancer detection was 73% and specificity 55% (AUC 0.63); efficacy was not sufficient. Urine values of clusterin were higher in individuals with bladder cancer (197.2 vs 67.7, p=0.0007). Sensitivity for bladder cancer detection was 49% and specificity 92% (AUC 0.75, LR+ 6.1, PPV+ 84%); diagnostic efficacy was sufficient. In conclusion, serum and urine clusterin can differ between bladder cancer patients and the control group. Urine clusterin could be the possible laboratory marker of bladder cancer. Further research is warranted to confirm findings in larger studies of various clinical status.