Carbohydrate Antigen 50: Values for Diagnosis and Prognostic Prediction of Intrahepatic Cholangiocarcinoma

Background and objectives: Cancer-associated carbohydrate antigen 50 (CA50) is a marker for detection of gastrointestinal cancers, especially of pancreatic and colon cancer. In this study, the power of CA50 as a diagnostic and prognostic marker was evaluated in intrahepatic cholangiocarcinoma (iCCA). Materials and Methods: Serum CA50 levels of iCCA patients and non-cholangiocarcinoma controls (non-CCA, including healthy persons and patients with benign biliary diseases and other gastrointestinal cancers) were measured using MAGLUMI^®800 CLIA analyzer. Diagnostic and prognostic values of serum CA50 levels were evaluated. Results: CA50 levels in the sera of iCCA patients were significantly higher than those of non-CCA controls (p < 0.001, Mann–Whitney U test). Using cut-off value of 25 U/mL, CA50 provided 65.9% sensitivity, 87.3% specificity, and 80.1% accuracy for diagnosis of iCCA. Serum CA50 levels were increased and associated with the severity of bile duct pathology. In addition, a higher level of CA50 was associated with poor clinical outcome and shorter survival in iCCA patients. Multivariate survival analysis by Cox regression model revealed the potential of CA50 as an independent poor prognostic indicator for iCCA, regardless of the age, sex, histological types, or tumor stages. Conclusions: CA50 can be a diagnostic and poor prognostic marker candidate for iCCA.