Technical Note: Analytical and Clinical Evaluation of Chemiluminescent Carcinoembryonic Antigen (CEA) by HISCL-5000 Immunoanalyzer

Objective. The carcinoembryonic antigen (CEA) is coupled with a diagnosis and prognosis for cancers. Methods. The analytical performance of CEA by chemiluminescent immunoassay (HISCL-5000, Sysmex, Kobe, Japan) was evaluated on the basis of precision, linearity, trueness, and method comparison. Clinical evaluation was performed by area under the receiver operating characteristic curve (AUROC) curve analysis for lung, stomach and colorectal cancers. Results. Total coefficient of variation (CV) (5.039% to 5.632%), linearity (0.5 to 982 ng/mL) and the percentage bias by trueness verification were less than desirable specifications for imprecision (6.4%) and bias (14.3%). The regression equation was y=0.354+0.957x(r=0.968) from method comparison. AUROC for lung, stomach, and colorectal cancers compared with normal healthy control ranged from 0.908 to 0.967 (cut-off 4.50 to 4.71 ng/mL), and compared with non-malignant benign disease, ranged from 0.578 to 0.721 (cut-off 8 to 20.70 ng/mL). Conclusions. CEA by HISCL-5000 immunoassay provided reliable performance. Comorbidities should be considered for interpretation of CEA.