Clinical Significance of the Urinary Bladder Cancer Antigen (UBCTM) Test in the Diagnosis of Bladder Cancer

Moon, Yong Cheul; Ryu, Dong Soo; Oh, Tae Hee

Abstract

PURPOSE: A new quantitative tumor marker, based on the combined measurement of urinary fragments of cytokeratin 8 and 18, namely the urinary bladder cancer antigen (UBCTM) test, has been proposed for the detection of bladder cancer. We compared the results of the UBC test, with voided urine cytology, for the diagnosis of bladder cancer to evaluate its diagnostic performance.
MATERIALS AND METHODS
The UBC concentrations were measured, using an immunoradiometric assay, in the urine of 15 healthy subjects (group I), 26 patients with other urological disease except bladder cancer (group II), 40 patients with active bladder cancer (group III) and 17 patients free of bladder cancer, as confirmed by cystoscopy at follow-up (group IV). The differences in the UBC test, with regard to stage, grade, tumor size, focality and history of recurrence, were also evaluated.
RESULTS
The mean UBC concentrations were 3.52micro gram/l, 45.76micro gram/l, 92.80micro gram/l and 20.51micro gram/l, for group I to IV, respectively, which were statistically different (p<0.05). There were significant differences regarding stage (p=0.044) and tumor size (p=0.036). However, no differences were founded in relation to the grade, shape, focality or history of recurrence. The optimal threshold for the UBC test, and the area under the ROC curve, were 12.8micro gram//l and 0.684, respectively. The sensitivity, specificity, positive and negative predictive values for the UBC test and urine cytology in groups III and IV were 50.0 and 30.0%, 88.2 and 100%, 90.9 and 100%, and 42.9 and 37.0%, respectively.
CONCLUSIONS
The UBC test appears to be useful for the detection of bladder cancer in terms of its superior sensitivity and negative predictive value over those of urine cytology. Further studies will be required for the clinical utility of the UBC test in the diagnosis and follow-up of bladder cancer.