Introduction: Enzyme-linked immunosorbent assay (ELISA) was used for analysis of serum mutant p53 protein, carcinoembryonic antigen (CEA), and epidermal growth factor receptor (EGFR). Serum samples were obtained from 48 patients with colorectal cancer (CRC) and a control group of twenty healthy individuals.
Results: The results demonstrated a significant increase of serum mutant p53, EGFR, and CEA levels in CRC patients compared to the control group (P<0.001 for 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 grades 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.
Conclusion: Thus, the simultaneous determination of p53 or EGFR combined with the CEA may increase the sensitivity to diagnose CRC patients and may aid in disease prognosis.