Preoperative chemotherapy unmasks underlying Barrett's mucosa in patients with adenocarcinoma of the distal esophagus

Background: Intestinal metaplasia of the distal esophagus frequently cannot be detected in patients with esophageal adenocarcinoma. It has therefore been questioned whether Barrett's esophagus is the primary precursor lesion of such lesions. We hypothesized that the underlying Barrett's mucosa may be masked by tumor overgrowth in the majority of these patients. Methods: The pretherapeutic endoscopy and biopsy records of 79 patients with locally advanced esophageal adenocarcinoma who had undergone preoperative chemotherapy were reviewed and compared to findings on restaging endoscopy/biopsy and subsequent resection and histopathologic analysis of the resected specimen. Results: Pretherapeutic endoscopy and biopsy showed associated Barrett's esophagus in 59/79 patients, whereas there was no evidence of associated intestinal metaplasia in 20/79 patients on extensive biopsies. Following neoadjuvant chemotherapy, Barrett's mucosa was unmasked and later documented by biopsy or histopathologic assessment of the resected specimen in 18 of the latter 20 patients. This resulted in an overall association of Barrett's mucosa with adenocarcinoma in the distal esophagus of 97.4% Conclusion: Underlying Barrett's mucosa is frequently masked by tumor overgrowth in patients with locally advanced adenocarcinoma of the distal esophagus.