Evaluation of -Catenin Expression in Relation to Staging and Grading of Colorectal Carcinoma – A Study Conducted in Jubilee Mission Medical College and Research Institute, Thrissur

Abstract

BACKGROUND Colorectal carcinoma is the most frequently encountered malignancy worldwide. The main cause of mortality associated with colorectal malignancy is tumour invasion and metastasis. The major genomic alteration that has been found in colorectal carcinoma is mutation in the adenomatous polyposis gene. Mutated APC causes unrestricted action of the Wnt signalling pathway which results in accumulation of the β - catenin protein in the nucleus responsible for cell proliferation, differentiation and enhanced survival of colorectal epithelial cells. Role of β - catenin expression as a prognostic marker needs to be studied. It will help in aiding the possibility of the future of anti β - catenin targeted chemotherapy for the treatment of colorectal cancers. METHODS A total of 85 samples from histopathologically proven cases of adenocarcinoma colon were taken. Histomorphological features and their immunohistochemical expression of β - catenin were studied. Data thus obtained was analysed using SPSS version 25. Histopathological diagnosis is considered as the gold standard. RESULTS Among the 85 samples of adenocarcinoma 9 case were stage T1 tumours, 24 were stage T2. 31 cases were stage T3, and 21 colorectal cancers were stage T4. Statistically significant correlation was obtained between tumour stage and β - catenin expression. (P value = < 0.001) With regard to tumour grade 24 out of 85 cases were well differentiated and 45 were moderately differentiated, 16 cases were poorly differentiated. Correlation of tumour grading and β - catenin expression also were statistically significant (P value = < 0.001). 45 out of 85 cases were having no nodal metastasis. 22 cases showed metastasis in 1 to 3 lymph nodes. 18 cases were N2. No statistically significant correlation was obtained between lymph node status and β - catenin expression. (P value = 0.003) CONCLUSIONS In this study the membranous, cytoplasmic and nuclear scores of β - catenin shows the linear progression with the advancing stages of colorectal carcinoma. So β - catenin can be used as a prognostic marker in malignant colorectal neoplasm. KEYWORDS Immunohistochemistry, β – Catenin, Colorectal Carcinoma