In rats, esophagogastroduodenal anastomosis (EGDA) without concomitant chemical
carcinogen treatment can lead to columnar-lined esophagus (CLE) including
metaplasia, dysplasia, and esophageal
adenocarcinoma (EAC). This study describes the morphology and phenotypic features of CLE and EAC in the rat model and compares them with the corresponding lesions in human
Barrett's esophagus (BE). Swiss roll preparations of esophagi of EGDA rats and biopsies from human BE containing specialized intestinal
metaplasia (SIM) and EAC were examined. The esophagi of EGDA rats showed
esophagitis, CLE, islands of multilayered epithelium (MLE), dysplasia and EAC. The CLE had features of specialized intestinal
metaplasia. MLE frequently occurred at the neo-squamocolumnar junction and occasionally in the mid-esophagus in isolated foci. Scattered mucinous cells in esophageal squamous epithelium were also found. The CLE and MLE in EGDA rats resembled the lesions described in human BE in morphology,
mucin features and expression of
differentiation markers (CK7, CK20,
Das-1,
villin, and pS2/TFF1). Invasive EAC in EGDA rat is of well-differentiated mucinous type, which is in contrast to the variably differentiated glandular type of
adenocarcinoma in human BE. p53, c-myc, and
cyclooxygenase 2 are expressed in both the rat and human SIM and EAC. These studies indicate that, not withstanding small differences, SIM and EAC induced in EGDA rats are similar to the corresponding lesions in human BE. EGDA rats may serve as a useful model to study the pathogenesis, molecular biology, and chemopreventive interventions of human BE and EAC.