Expression of P53 oncoprotein in benign and malignant lesions of large bowel

摘要

AIMS To investigate expression of P53 oncoprotein in benign and malignant lesions of large bowel as well as the relationship between 53 expression and clinico-pathological factors. METHODS S-P immunohistochemistry was used to detect P53 protein in large bowel tissues of 146 cases with benign and malignant lesions. RESULTS All normal large bowel mucosas and non-neoplastic polyps were negative for P53 protein. However, the positive rates of P53 protein in adenomas, paracancerous mucosas and carcinomas were 18.18% (2/11), 13.21% (7/53) and 42.11% (32/76) respectively. Yet the p53 expression in both adenomas and paracancerous mucosas presented only very occasional cells weak stain, whereas 75 percent of 53 positive cancers gave very intense stain ( + + -+ + + ). The incidences 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 those 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). But no relationship between p53 expression and massive type, tumor size, location, Dukes stage and 3-year survival was found in this study. CONCLUSIONS p53 gene mutation and overexpres-sion are common in colorectal cancers, and seem associated with histological type, progression and lymph node metastases of colorectal cancer.