Clinical significance of combined determination of serum amino acids, CEA and CA19-9 in the diagnosis of colorectal cancer

Objective To dynamically determine the serum levels of amino acids, carcinoembryonic antigen (CEA), and CA19-9 for exploring the significance of their changes in the diagnosis of colorectal cancer. Methods Thirty patients with colorectal cancer diagnosed in the General Hospital of the PLA Rocket Force from August to December 2017 were selected, and 30 colorectal adenoma as control. Fifty kinds of serum amino acids were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and CEA and CA19-9 levels by electrochemiluminescence. Statistical methods were used to identify significant changes in amino acids. The area under the ROC curve (AUC) for the combined detection of CEA and CA19-9 in colorectal cancer was calculated and compared with the area under the ROC curve for the determination of colorectal cancer by CEA and CA19-9 alone. Results Compared with colorectal adenomas, there were changes in level of five amino acids in colorectal cancer patients: ethanolamine (EtN) and citrulline (Cit) sig