Immunohistochemical Expression of p53 and bcl-2 in Colorectal Adenomas and Carcinomas Using Automated Cellular Imaging System

Background & Objective: The current approaches to reduce the risk of colorectal carcinoma are through the detection and removal of the precursor lesion adenomatous polyps . The studywas conducted to evaluate the immunohistochemical expression of p53 and bcl-2 in colorectaladenomas and carcinomas.Patients and Methods: A total of 86 cases, 33 colorectal adenomas, 33 colorectal adenocarcinomas and 20 samples of non -tumerous colonic tissue as control, were included in this retrospective study. Sections were stained immunohistochemically for p53 and bcl-2. Scoring was performedusing Digimizer software. Data were analyzed using SPSS program (Statistical Package for Social Sciences) version 16 and Microsoft Office Excel 2007. Results: The frequency of p53 positive cases was significantly higher in carcinoma than adenoma while the frequency of bcl-2 positive cases was significantly higher in adenoma than carcinoma.p53 expression was significantly higher in large sized adenomas, villous configuration, severe dysplasia, and multiple lesions. Bcl-2 expression showed significantly correlated with adenomas of small size, solitary, tubular, and mild dysplasia. There was a significant correlation between bcl-2 expression and non-mucinous carcinoma and a negative correlation with tumor size. Therewas an inverse relationship between bcl-2 and p53 expression in both colorectal adenomas and carcinomas. Conclusion: p53 overexpression is a late event in colorectal tumorigenesis. bcl-2 may play an important role in the early stage of adenoma-carcinoma sequence.

کلیدواژه ها:

p53 Antigen ، c-bcl-2 Proto-Oncogene ، Adenoma ، Colorectal Carcinomas