Epidermal Growth Factor Receptor Expression of Colorectal Carcinoma in Nigerian Patients

Colorectal carcinoma is the third most common cancer worldwide. With the push towards targeted therapy in the management of metastatic colorectal carcinoma using anti-EGFR monoclonal antibody, this study aimed to determine the rate of Epidermal Growth Factor Receptor (EGFR) expression in Colorectal Carcinoma, compare the clinicopathological features with the EGFR status and determine if EGFR expression in colorectal carcinoma is of any prognostic significance.

The clinical and demographic data of 54 patients who had colectomy specimens sent to the Pathology Department at the UCH, Ibadan were reviewed to confirm the diagnosis, tumour grade and other clinico-pathological parameters. EGFR expression was assessed on the archival Formalin Fixed Paraffin Embedded (FFPE) blocks using immunohistochemical staining technique. Pearson's chi square test was used to correlate the EGFR status and the clinicopathological features of the tumour.

Epidermal Growth Factor Receptor was expressed in 85.2% of colorectal carcinoma cases. There was an association between EGFR status, depth of tumour invasion and tumour size having P value of 0.05 and 0.043 respectively but there was no association with other clinicopathological parameters. There was no correlation between intensity of staining, percentage of tumour stained and clinicopathological parameters.

This study demonstrates that most cases of colorectal carcinoma diagnosed in the University College Hospital, Ibadan, in the study period showed expression for EGFR. We found that there was an association between depth tumour invasion and tumour size with EGFR expression, suggesting that most EGFR positive colorectal carcinomas are large and show deeper invasion by the tumours. Thus, EGFR positive tumours most likely have poor prognosis.