Assessing the Clinical Benefit of UBC Rapid in the Surveillance and Initial Diagnosis of Bladder Cancer.

Abstract

Several studies have shown that abnormal urine levels of cytokeratins 8 and 18 are associated with bladder cancer. However, the clinical benefit of the UBC (urinary bladder cancer) Rapid assay has remained unclear. We performed the UBC Rapid assay and voided cytology in 336 patients-297 in surveillance for non-muscle-invasive bladder cancer and 39 with newly diagnosed bladder cancer. The sensitivity, specificity, positive predictive value, and negative predictive value were calculated by contingency. We also controlled for the patients with positive UBC Rapid findings but negative cystoscopy findings to prove the former's ability to provide an anticipatory diagnosis. We diagnosed 27 recurrences (9.8%). Overall, the sensitivity of the UBC Rapid assay was better for the higher risk groups and after adding the cytology findings. The only independent predictor of a positive UBC Rapid assay was the tumor size. Of the 81 patients with positive UBC Rapid findings without positive cystoscopy findings, 8 (10%) had developed a recurrence within the first year. Avoiding cystoscopy for the patients with UBC Rapid negative results could avoid 184 cystoscopies (66%) but would result in missing 7 of 13 high-risk recurrences. The performance of the UBC Rapid assay improved with increasing tumor size. Limiting cystoscopies to patients with UBC Rapid positive results could result in a reduction in surveillance cystoscopies but could result in missing high-risk recurrences. Finally, the UBC Rapid assay was not useful for anticipatory diagnoses.