Expression of E-cadherin in Colorectal Cancer and Its Association with Morphological Features

Abstract

BACKGROUND Early diagnosis of colorectal cancer is associated with a good prognosis and uncovering the biological mechanisms underlying pathogenesis and progression of this cancer form the recent focus of research. E-cadherin is one of the strong intercellular adhesion molecules in epithelial cells and one of the best characterized markers of epithelial-mesenchymal transition. The objectives of this study were to assess the pattern of expression of E-cadherin in colorectal cancer in patients from a medical college in Kerala, India and also determine the association between the expression of E-cadherin and different morphological parameters as well as the grade and stage of the tumour. METHODS All specimens of histologically diagnosed colorectal cancers received in the department were included in the study. Immunohistochemical staining of formalinfixed paraffin-embedded tissue was done. The intensity of E-cadherin staining was scored and analyzed for different tissues. Frequency tables of different variables were analyzed using the chi-square test. The significance of the correlation between different variables was assessed using Fischer’s exact test. P-value < 0.05 was considered statistically significant. RESULTS A total of 43 specimens of histologically diagnosed colorectal cancers were analyzed for the study. The mean age of the participants was 58 years. Majority of the tumours were < 5 cm in size. Both homogenous (55.8 %) and heterogeneous staining (44.2 %) were noted in the E-cadherin staining pattern among the participants. In patients with low E-cadherin index, 12 of them showed a heterogeneous pattern of expression. E-cadherin expression was not statistically associated with tumour differentiation in the patients. CONCLUSIONS There is a significant difference in E-cadherin expression between low and highgrade tumours of colorectal cancer. High-grade tumours showed a more heterogeneous staining pattern correlating with increased invasiveness of the tumour. The heterogeneous pattern of staining in E-cadherin among adjacent cells of tumour results from reduced expression of the protein in the tumour. KEY WORDS E cadherin, Colorectal Cancer, Cancer Marker.