Enzyme-linked immunosorbent assay (ELISA) was used for analysis of serum mutant p53 protein and epidermal growth factor receptor (EGFR) and electrochem-iluminescence immunoassay (ECLIA) was used for analysis of carcinoembryonic antigen (CEA). Serum samples were obtained from 48 patients with colorectal cancer (CRC) and a control group of twenty healthy individuals. The results demonstrated a significant increase of serum mutant p53, EGFR, and CEA levels in CRC patients compared to the control group (P < 0.001for each). Mutant p53 protein was significantly different in the different CRC grades (P = 0.028). p53, CEA, and EGFR can differentiate successfully between different CRC Duke's stages and normal control (P < 0.001 for each).Sensitivities of p53, CEA, and EGFR were 39.6, 31, and 71%, respectively. There was no correlation between CEA, EGFR and p53 indicating that these variables were independent. Positive status of serum CEA and/or p53 was found in 29 out of 48 (60%) patients. Also, positive status of serum CEA and/or EGFR was found in 39 out of 48 (81%) patients. The simultaneous determination of p53 or EGFR combined with CEA may increase the sensitivity to diagnose CRC patients and may aid in disease prognosis.
EGFR; CEA; Colorectal carcinoma; Mutant p53 protein; Area under curve variables; Monoclonal antibodies; Tyrosine kinase activity.