RESUMO
BACKGROUND AND METHODS: p53 protein expression was studied immunohistochemically in 73 colorectal adenocarcinomas, using monoclonal antibody D07 in alcohol fixed, paraffin embedded tissue. RESULTS: Immunoreactivity was found in 49% of specimens, detected in the nuclei of the cancer cells. There was no significant correlation between the expression of p53 and the clinicopathological parameters age, sex, tumor size and site, lymphatic invasion, and lymph node metastasis. However, the p53 overexpression correlated with stage of disease, histologic grade, vascular invasion and with the presence of villous or tubular adenomas in the resected specimens. The p53 positive tumors showed a higher rate of recurrence than the p53 negative tumors; however, the difference was not statistically significant. The short-term survival rate (follow-up 7-48 months, median 30 months) was 90% for 20 patients with p53 negative tumors, and 65% for the patients with p53 positive tumors; a significant difference in the survival between the two groups of patients was found. CONCLUSIONS: These results suggest that in colorectal carcinoma, immunohistochemical detection of p53 protein can be used along with other established indicators to asses prognostic outcome, specially to identify patients with a poor short-term prognosis.