P53 PROTEIN EXPRESSION AND PROGNOSIS IN SQUAMOUS-CELL CARCINOMA OF THE ESOPHAGUS

Background. The p53 gene product is known to regulate cell growth and proliferation. Whereas the wild-type p53 protein suppresses cell growt h, the mutated p53 protein acts as an oncogene. Mutations in the p53 g ene usually result in p53 protein stabilization and accumulation; so t hat the gene product can be detected by immunohistochemistry. Recently , the immunohistochemical detection of the p53 protein was associated with prognosis in breast, colorectal, and other types of cancer. Howev er, its prognostic role in esophageal cancer remains to be elucidated. Methods. p53 expression in formalin fixed, paraffin embedded samples of 204 patients with primary squamous cell carcinoma of the esophagus, who underwent esophageal resection, were analyzed immunohistochemical ly with DO-1, a monoclonal antibody that detects wild-type and mutant forms of p53. The relationship between p53 immunoreactivity and progno stic factors was determined by the Chi-square test, and the prognostic impact of p53 protein expression was analyzed using univariate and mu ltivariate survival analyses. Results. In 137 of 204 tumors (67.2%), n uclear immunoreactivity for the p53 protein was detected. There was no correlation with sex, age, pathologic tumor (pT) category, pathologic lymph node (pN) category, metastasis (M) category, residual cancer (R ) category, histologic grade, or preoperative radiation therapy. In co ntrast to clinicopathologic parameters, p53 expression was not correla ted with prognosis in univariate and multivariate survival analyses. C onclusions. The p53 protein can be detected by immunohistochemistry in a high percentage of squamous cell carcinomas of the esophagus. Howev er, the overexpression of the p53 gene product has no impact on the pr ognosis.