Published online Dec 15, 1996. doi: 10.3748/wjg.v2.i4.236
Revised: August 21, 1996
Accepted: September 14, 1996
Published online: December 15, 1996
AIM: To investigate the expression of P53 oncoprotein in benign and malignant lesions of the large bowel as well as the relationship between p53 expression and clinicopathological factors.
METHODS: Immunohistochemistry was used to detect P53 protein in large bowel tissues of 146 cases with benign and malignant lesions.
RESULTS: All normal large bowel mucosae and non-neoplastic polyps were negative for P53 protein. However, the positive rates of P53 protein in adenomas, paracancerous mucosae and carcinomas were 18.18% (2/11), 13.21% (7/53) and 42.11% (32/76), respectively. The P53 expression in both adenomas and paracancerous mucosae presented only weak staining, whereas 75% of p53 positive cancers displayed very intense staining (++ or +++). The rates of P53 protein detection in poorly differentiated carcinoma and mucous carcinoma were 63.64% (7/11) and 62.5% (10/16), respectively, which were much higher than that of well/moderately differentiated carcinomas (30.16%, 15/40) (p < 0.05), and the carcinomas with marked positive p53 expression were more likely to penetrate the bowel wall and metastasize to lymph nodes (p < 0.05). However, no relationship between p53 expression and massive type, tumor size, location, Dukes stage or 3-year survival was found in this study.
CONCLUSION: P53 gene mutation and overexpression are common in colorectal cancers, and seem to be associated with histological type, progression and lymph node metastasis of colorectal cancer.