Objective: The purpose of this study was to use biomarkers to assess for cancer risk in Barrett's esophagus patients with either squamous islands or complete reversal of their intestinal metaplasia to squamous epithelium.
Methods: The biomarkers included proliferation characteristic using Ki-67, p53 abnormalities using immunohistochemical methods with two antibodies, DO-1 and DO-7, and ornithine decarboxylase (ODC) activity.
Results: Eleven patients had complete reversal produced by a combination of acid suppression and thermal injury (multipolar electrocoagulation). Ki-67 staining was indistinguishable from that of normal squamous esophageal epithelium, i.e., basal layer staining only. All 11 cases were negative for p53. ODC activity was low and in the range for normal squamous epithelium. Fourteen patients had squamous islands (partial reversal) after prolonged proton pump inhibitor therapy. Multilayer Ki-67 staining occurred in nine cases (64%), and six (43%) had areas of positive p53 staining.
Conclusions: Initial biomarker studies suggest that completely reversed squamous epithelium is biologically similar to normal squamous epithelium and of low cancer risk. In contrast, partial reversal, manifest as squamous islands, is accompanied by biomarker abnormalities.