The power to predict with biomarkers: carbohydrate antigen 19-9 (CA 19-9) and carcinoembryonic antigen (CEA) serum markers in intrahepatic cholangiocarcinoma

Carbohydrate antigen 19-9 (CA 19-9) and carcinoembryonic antigen (CEA) are the most studied tumor markers in intrahepatic cholangiocarcinoma (iCC) and are elevated in 85 and 40%, respectively (1). A recent publication proposed that serum biomarkers enhance the predictive power of the American Joint Committee on Cancer 8th edition (AJCC/UICC) and the Liver Cancer Study Group of Japan (LCSGJ) staging systems in resectable iCC (2).