Immunohistochemical Study of p53 Protein Expression in Colorectal Tumors

Lee, Mi Sook; Suh, Chae Hong; Lim, Sung Chul

Abstract

The aims of this study were to assess the role of p53 overexpression in colorectal tumorigenesis and the association with clinicopathological features. The immunohistochemical results were semiquantitatively assessed. Expression of aberrant p53, tumor-suppressor gene product, was studied immunohistochemically using a monoclonal antibody in 11 nonneoplastic polyps, 19 tubular adenomas, 9 villous adenomas, and 48 colorectal carcinomas. Five out of 11 nonneoplastic polyps, 14 out of 19 tubular adenomas and one out of 9 villous adenomas expressed p53 protein. Seven out of 24 colorectal carcinomas without lymph node metastasis and 14 out of 24 colorectal carcinomas with lymph node metastsis expressed p53 protein. The case of more than 75% positivity of p53 in colorectal carcinoma with lymph node metastasis was seven out of 24, but that in lymph node negative group was two out of 24. In the colorectal carcinoma with lymph node metastasis group; metastatic intranodal neoplastic cells were expressed positively for p53 in 10 out of 14 cases and zero out of 10 cases in group of positive and negative expression of primary lesions, respectively. p53 protein expression was not significantly correlated with variable clinicopathologic features such as age, sex, tumor location, tumor size, differentiation and Dukes' stage. It is suggested that p53 protein overexpression could be a early event in pathogenesis of colon cancer but is not involved in progression of villous adenoma to adenocarcinoma. p53 overexpression seems to be involved in metastatic ability of colorectal carcinomas.