Evaluation of Expression of EGFR, HER-2 and COX-2 in Colorectal Cancer

EGFR and HER-2 are two members of ERbB/HER family of Type I Transmembrane growth factor receptors. Cox2 is an enzyme responsible for the conversion of arachidonic acid to prostaglandins, which has a major role in angiogenesis and can modelate tumor growth. The aim of this study was to determine the level of expression of EGFR, HER-2 and Cox2 in colorectd cancer. IHC study was performed in paraffin-embedded blocks of 47 patients underwent colectomy due to colorectal cancer in Modarres Hospital, Tehran, Iran from 2008 to 2009. Three separated pathologists analyzed the slides after complete IHC staining for EGFR, HER-2 and COX-2. EGFR, HER-2 and Cox2 revealed over expression in colorectal cancer as 80.9%, 25.5% and 72.4% respectively, EGFR revealed no statistically significant association with clinicopathologic parameters, but Cox2 overexpression exhibited statistically significant association with higher stages tumors (III, IV) (P value: 0.037) and tumor with lymph node metastasis(P= 0.005). On the other hand, HER2 overexpression showed statistically significant association with lower grade (well and moderately differentiation) tumors (P= 0.042). According to over expression of three markers, EGFR, HER-2, and COX-2 in colorectal cancers, using drugs that act against these receptors and investigation of survival improvement of patients with these drugs in other studies are recommended.