Purpose: The purpose of this study was to determine the prognostic impact of epidermal growth factor receptor (EGFR) and Her2/neu protein expression in colorectal cancer.
Methods: Immunohistochemistry was performed in paraffin-embedded specimens of 106 colorectal carcinomas for the assessment of EGFR and Her-2 expression. The results were correlated with traditional clinicopathologic parameters and patient outcome.
Results: Membranous expression of EGFR was found in 50 cases (47.16%) and cytoplasmic expression in 32 cases (30.19%). Membranous overexpression of Her-2 was identified in six cases (5.66%) whereas cytoplasmic expression was found in 18 cases (16.98%). The correlation with other clinicopathologic parameters demonstrated a statistically significant expression of membranous EGFR in the older age group and a statistically significant expression of membranous Her-2 in patients with negative lymph nodes. None of the other parameters or patient prognosis was associated with EGFR or Her-2 membranous expression. Cytoplasmic expression was not related with any of aforementioned parameters.
Conclusion: Conventional immunohistochemistry was unable to reveal any association between EGFR expression and outcome predicted by the biologic role of EGFR in tumor behavior. Her-2/neu is not a pivotal pathway in colorectal cancer progression because it seems to be expressed in early stages of colorectal cancer.