Analytical and clinical evaluation of a new urinary tumor marker: bladder tumor fibronectin in diagnosis and follow-up of bladder cancer.

Bladder cancer is the fourth most common malignant neoplasm in men and the tenth most common in women. Cystoscopy presents the gold standard for detection and monitoring of bladder cancer. However, it is an invasive and expensive procedure. Therefore, development of biomarkers for the purposes of screening, diagnosis and prediction of the prognosis in bladder cancer is required. Bladder tumor fibronectin is one of the new urinary tumor markers. The aim of this study is to evaluate the diagnostic performance of urinary bladder tumor fibronectin in detecting and monitoring bladder cancer. A total of 75 patients with the diagnosis of bladder cancer, 20 patients with the diagnosis of benign prostatic hyperplasia, 7 patients with the diagnosis of prostate cancer between the years 1996-2000, and 28 age-matched healthy individuals, were enrolled in the study. The patients were diagnosed by cystoscopy, with histopathological evaluation of the tumor, as having superficial or invasive bladder cancer. Patients were followed-up clinically with data pertinent to disease recurrence and progression. Bladder tumor fibronectin (BTF; ng/ml) was determined by solid phase, two-site chemiluminescent immunometric commercial diagnostic assay developed for the Immulite automated immunoassay system (Diagnostic Products Corporation, Los Angeles, CA, USA). All measured values were normalized by urinary creatinine, and the obtained data were evaluated by receiver-operating characteristics (ROC) curve analysis. Optimal cut-off was established at 43.4 ng/mg. This cut-off rendered overall sensitivities of 72% and specificity of 82.1%. The analytical evaluation of the BTF test displayed promising results in terms of a non-invasive in vitro test in the diagnosis of bladder cancer. Although it was not satisfactory in prediction of recurrence or progression of the disease, it correlated well with the stage, one of the most reliable prognostic factors. In conclusion, the urinary bladder tumor fibronectin test warrants further clinical evaluation.