Evaluation of tumor biomarkers and cytokines in the detection and follow up of colorectal cancer

ABSTRACT
Objectives: To use a panel of seven tumor markers for the detection and follow up of colorectal cancer. To compare the diagnostic utility of the tumor markers with that of the standard methods. To construct ROC curve for the purpose of the best detection of the studied cancer.
Patients and methods: Fifty two colorectal cancer patients and 30 apparently healthy individuals as a control group were studied. They were tested for: carcinoembryonic antigen (CEA), cancer antigen 19-9, cancer antigen 72-4 and tissue polypeptide antigen (TPA), two cytokines [interleukin-6 (IL-6)] and vascular endothelial growth factor (VEGF)] by using ELISA. Twenty colorectal cancer patients were followed up for a period of 3-5 months after surgical resection.
Results: There was a significant difference (p<0.001) in the diagnostic utility between cancer and control group for all the seven tumor markers. In colorectal cancer group, a significant difference (p<0.001) in the serum concentration of CEA, TPA, IL-6, VEGF and CRP was detected according to the stage of cancer. No significant difference was shown for CA 19-9 and CA 72-4. Using ROC curve analysis, CEA was the best diagnostic test. In the follow up group, a significant reduction was found for all the seven investigated parameters.
Conclusion: CEA, CA 19-9, CA 72-4, TPA, IL-6, VEGF and CRP are of considerable diagnostic, prognostic and follow up utility. ROC curve is used to enhance the diagnostic accuracy of the studied tumor markers.
Keywords: Colorectal cancer, tumor biomarker, interleukin-6, vascular endothelial growth factor.