Comparative study of CEA and CA19-9 in esophageal, gastric and colon cancers individually and in combination (ROC curve analysis)

Abstract

Objective:To determine the clinical serum levels of carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9), individually and in combination, for the diagnosis of 50 healthy subjects and 150 cases of esophageal, gastric, and colon cancers.Methods:The sensitivities of the two markers were compared individually and in combination, with specificity set at 100%. Receiver operating characteristic (ROC) curves were plotted.Results:Serum CEA levels were significantly higher in cancer patients than in the control group. The sensitivity of CEA was determined:in esophageal cancer, sensitivity=28%, negative predictive value (NPV)=61.72%, and AUC=0.742 (SE=0.05), with a significance level of PPPP=0.2054. In gastric cancer, sensitivity=42%, NPV=63.29%, and AUC=0.679 (SE=0.05), with a significance level of PP=0.1670. The following were the sensitivities of CEA/CA19-9 combined:in esophageal cancer, sensitivity=42%, NPV=63.29%, SE=0.078 (95% CI:0.0159-0.322); gastric cancer, sensitivity=58%, NPV=70.42%, SE=0.072 (95% CI:-0.0866-0.198); and colon cancer, sensitivity=72%, NPV=78.12%, SE=0.070 (95% CI:0.137-0.415).Conclusion:CEA exhibited the highest sensitivity for colon cancer, and CA19-9 exhibited the highest sensitivity for gastric cancer. Combined analysis indicated an increase in diagnostic sensitivity in esophageal and gastric cancer compared with that in colon cancer.

Keywords

• Carcinoembryonic antigen
• carbohydrate antigen 19-9, human
• Receiver operating characteristic curve
• sensitivity and specificity