POTENTIAL APPLICATION OF P53 AS AN INTERMEDIATE BIOMARKER IN BARRETTS-ESOPHAGUS

Diagnosis of the neoplastic progression in Barrett's esophagus using t he histologic classification of dysplasia is frequently difficult. The tumor suppressor protein p53, when mutated, confers a promoter effect on cell growth. The purpose of this study was to evaluate the applica bility of p53 as an intermediate biomarker of malignancy in Barrett's esophagus. Archival analysis of 100 biopsy specimens of Barrett's esop hagus and 10 esophageal adenocarcinomas were compared with 35 chronic esophagitis biopsy specimens. Immunocytochemistry using an anti-p53 mo noclonal antibody was performed and elevated immunoreactivity quantita ted microscopically. Data were analyzed using a logistic regression mo del. Significant p53 immunoreactivity occurred as follows: chronic eso phagitis (0%), Barrett's esophagus without dysplasia (10%), with low-g rade dysplasia (60%), with high-grade dysplasia (100%), and adenocarci noma (70%). All cases of Barrett's esophagus were significantly immuno reactive when compared with the chronic esophagitis cases (p = 0.001). There was an increase in p53 immunoreactivity as the histologic class ification progressed toward adenocarcinoma (p = 0.001). progression to high-grade dysplasia may be predicted based on p53 immunoreactivity. These findings suggest a role for p53 as an intermediate biomarker in Barrett's esophagus.