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). The authors of this multicenter study come from 16 experienced hepatobiliary centers in North America, Asia, Australia, and Europe. The study is based on a large patient population of 805 patients undergoing resection for histologically proven iCC. Patients with missing CA 19-9 data, R2 resection, or presence of extrahepatic disease at time of surgery were excluded from the study. The objectives of the study was to define the best survival cut-off values for CA 19-9 and CEA and to investigate whether the integration of these biomarkers increase survival prediction of the AJCC/UICC and the LCSGJ classification for iCC (2). The study identified best cut-offs of CA 19-9 and CEA, which were associated with postresectional survival. In addition, the authors suggest that the inclusion of preoperative CA 19-9 and CEA in AJCC/UICC and LCSGJ staging systems may improve the prognostic survival prediction after resection for iCC