Expression of Beta-Catenin in Colorectal Carcinoma and its Association with Various Clinicopathological Parameters

Introduction: Colorectal Carcinoma (CRC) is the third most commonly diagnosed cancer and the second leading cause of cancer related mortality globally. It is a source of concern for researchers worldwide and hence, a lot of emphasis is being given towards early detection and targeted drug therapy to improve the survival rate. Aim: To study the expression of beta-catenin in colonic polyps, adenomas and CRC and to associate beta-catenin expression with various clinicopathological features. Materials and Methods: This was a prospective cross-sectional study conducted in the Department of Pathology, Kalinga Institute of Medical Sciences, Bhubaneswar, Odisha, India from September 2018 to August 2020. Colonoscopic biopsies, mucinous carcinoma and poorly preserved tissue were excluded. Histopathological study and Immunohistochemistry evaluation of beta-catenin was done. Statistical analysis was done by using appropriate tests. A p-value of less than 0.05 was taken as statistically significant. Results: Out of 80 cases, 40 cases were benign lesions Non neoplastic polyp and adenoma) and 40 cases were adenocarcinoma. It was observed that benign lesions had maximum cases with preserved membranous expression (36/40) and very few cases (4/40) showed cytoplasmic expression of beta-catenin. But in carcinoma, high cytoplasmic expression was seen in 20/40 (50%) whereas 8/40 (20%) cases had nuclear positivity. Membranous beta-catenin expression was significantly higher in benign lesions than in the malignant lesions (IS:8.75±3.09 versus 4.30±2.70) respectively; (p<0.0001). But cytoplasmic beta-catenin expression was low in benign lesion as compared to malignant lesion (IS: 2.07±3.46 versus 5.35±3.14), respectively; (p<0.0001). However, nuclear beta-catenin expression was extremely low in benign lesions than in malignant lesions (0.08±0.47 versus 1.90±3.49), respectively; (p=0.0016), this difference was statistically significant. Conclusion: The present study demonstrates the change in beta-catenin expression with gradual transition from predominantly membranous pattern to cytoplasmic or nuclear as we progress from normal colorectal tissues to polyps, benign premalignant lesions and malignant neoplasms. This property of beta-catenin helps in determining malignant potential of various premalignant neoplasms of large intestine which in turn helps in initiating early prophylactic treatment.