Verification of WFA-Sialylated MUC1 as a Sensitive Biliary Biomarker for Human Biliary Tract Cancer

Background: The diagnostic accuracy of biliary cytology is limited. A novel sandwich enzyme-linked immunosorbent assay that combined Wisteria floribunda agglutinin (WFA) and anti-sialylated mucin 1 (MUC1) monoclonal antibody to target bile samples was recently developed. This study was designed to verify the diagnostic accuracy of WFA-sialylated MUC1 as a sensitive biliary biomarker for human biliary tract cancer. Methods: Bile samples from 27 patients with benign disease and 174 patients with biliary tract cancer were analyzed. A receiver-operated characteristic curve analysis for biliary WFA-sialylated MUC1 and serum CA19-9 levels was performed to determine the cutoff value for the prediction of the presence of biliary tract cancer. Results: Biliary WFA-sialylated MUC1 levels were significantly higher in the biliary tract cancer group compared with the benign group (P < 0.001). The cutoff value of WFA-sialylated MUC1 for discriminating biliary tract cancer was 10.5. The sensitivity of WFA-sialylated MUC1 in discriminating biliary tract cancer was much higher (82.2 %) than that of cytology (23.6 %) when this cutoff value was used. The cutoff value of serum CA19-9 for discriminating biliary tract cancer was 38 IU/L in the same cohort. All patients with biliary WFA-sialylated MUC1 and serum CA19-9 above the cutoff values had biliary tract cancer, and no patient with benign disease was categorized in this group. Conclusions: Biliary WFA-sialylated MUC1 is a useful biomarker for the differentiation of biliary tract cancer. The sensitivity of WFA-sialylated MUC1 was clearly higher than that of biliary cytology. Further data collection is necessary to validate the clinical usefulness of this biomarker.