The purpose of the present study was to assess a new quantitative urinary
tumor marker for
transitional cell carcinoma of the urinary bladder (TCC), measuring fragments of
cytokeratin 8 and 18 in the urine (UBC). Urine samples of 355 individuals (77 healthy volunteers, 111 patients with benign urologic disorders, 167 patients with histologically proven
bladder cancer) were examined for the presence of
UBC antigen. Samples of all patients were obtained prior to
therapy. Compared to healthy volunteers or patients with benign
urologic disease, patients with TCC had significantly higher median urinary levels of
UBC antigen (0 vs. 4.18 vs. 7.46 microg/g
creatinine; p<0.001, and p<0.01, respectively).
UBC antigen levels were positively correlated with
tumor grade and stage. Patients with invasive TCC had significantly higher levels of
UBC antigen than patients with superficial TCC (p<0.001). Elevated levels of
UBC antigen were also found in patients with benign urologic disorders (median: 4.18 microg/g
creatinine vs. 7.46 microg/g
creatinine in
cancer patients). Using a cutoff of 14.06 microg/g
creatinine (corresponding to 95% specificity in the group of healthy individuals), sensitivity of
UBC antigen ranged between 21.6% (pTa) and 75% (pT4). Overall specificity was 76.6%. Based on our data we conclude that the
UBC antigen test in its current format is not clinically useful for detection of
bladder cancer.