Evaluation of two new urinary tumor markers: bladder tumor fibronectin and cytokeratin 18 for the diagnosis of bladder cancer.

Abstract

Our objectives were to evaluate the diagnostic value of two new urinary tumor markers, cytokeratin 18 (CK18) and bladder tumor fibronectin (BTF), for the detection and monitoring of bladder cancer. The study comprised 931 urine samples belonging to 402 subjects: 112 individuals under suspicion for a primary bladder tumor (group 1); 104 bladder cancer patients under scheduled follow-up (group 2); 109 bladder cancer patients receiving intravesical instillations (group 3); 45 patients with other urological diseases (group 4); and 32 healthy subjects (group 5). Voided urine samples were collected before cystoscopies, between them and before intravesical instillations. CK18 and BTF tests were measured by chemiluminescent immunoassays. Optimal receiver operating characteristic cutoffs of 7.4 microg/L for CK18 and 52.8 microg/liter for BTF rendered overall sensitivities of 66.2% for CK18 and 80.0% for BTF at specificities of 88.4 and 74.7%, respectively. Urinary cytology provided a sensitivity of 29.2% at a specificity of 99.1%. Sensitivities were 80.8, 74.2, and 82.3% for BTF and 71.1, 77.4, and 64.7% for CK18 for groups 1 to 3, respectively. False positive rates were higher for BTF in all groups of patients. Elevated urinary tumor markers during the monitoring of patients with bladder cancer could detect recurrence sooner than scheduled cystoscopies. Persistence of negative markers was greatly indicative of free of disease status in follow-up. CK18 and BTF in urine may eventually prove to be of benefit for specific patients with bladder carcinoma given its higher sensitivity compared with cytology. In selected patients, namely those with persistent negative urinary CK18 and BTF, the number of cystoscopies could be reduced.