Value Of Bile Carcinoembryonic Antigen Assay In Diagnosis Of Hepatic Metastasis From Colorectal Cancer

Objective:We measured carcinoembryonic antigen(CEA) levels in peripheral and portal vein and bile from patients with colorectal cancer(CRC).The aim of this study was to evaluate the change of bile CEA levels in patients with CRC,the relation between bile CEA levels and liver metastasis(LM) and the relation between the prognosis of CRC and bile CEA levels.Methods:Three groups were enrolled in our study;Group 1(27) patients with CRC without LM;Group 2(14) patients with LM from CRC;Group 3(20) is the controlled group,including patients with benign biliary diseases(cholelithiasis or cholecystitis). Only bile CEA was measured in group 3.Results:The median level of bile CEA in controlled group was 1.73ng/ml.The median CEA levels in peripheral vein and bile from group 2,i.e.patients with LM from CRC(43.51ng/ml,314.27ng/ml) were much higher than those from group 1 (5.77ng/ml,13.07ng/ml),of which the change of bile CEA was more distinguishing. The sensitivity(proportion of patients with CEA levels higher than 10.0ng/ml) of bile was better than that of peripheral vein(70.7%Vs 48.8%,P=0.035).In group 1,we found a difference(P=0.047) in CEA from peripheral vein with regard to tumor stage (P=0.042),whether lymph node was invaded(P=0.025) and whether nerve was invaded,while in bile CEA,the difference is with regard to tumor differentiation.In patients with multiple LM,bile CEA levels and sensitivity elevated rapidly (920ng/ml,100%).The correlation between diameter of LM and bile CEA level is better than that of peripheral vein CEA.In prognosis,CEA levels of peripheral vein (P=0.067) seemed to be more accurate than bile(P=0.240).Conclusion:The level of normal bile CEA is lower than 5.0ng/ml.In patients with CRC,bile CEA elevates significantly,this difference remains obvious when comparing CRC with or without LM.The sensitivity is much better than peripheral vein.Bile CEA level is relevant to the number and size of LM but has little to do with the primary tumor.However,CEA levels of peripheral vein seemed to be better than bile in predicting the prognosis of CRC.