The neoplastic potential of columnar-lined (Barrett's) esophagus.

Reflux of gastric contents is the most important factor contributing to the development of a columnar-lined esophagus (CLE). CLE should be considered a "mosaic" of cells, glands, and architectural types showing variable degrees of maturation towards intestinal and gastric epithelium. Dysplasia refers to an unequivocally neoplastic alteration in the epithelium. High-grade (severe) dysplasia consists of neoplastic cellular and/or architectural changes within the columnar epithelium, without invasion through the basement membrane. The prevalence of dysplasia is usually 5% to 10%. Dysplasia has been found in the vast majority in the specialized columnar-type or intestinal-type epithelium. Adenocarcinoma in CLE is most often seen in males. At the time of diagnosis transmural tumor infiltration is found in 60% to 88% of patients, and lymph node invasion in 55% to 74% of patients. The prognosis is poor with a low 5 year survival. Estimates of incidence of cancer vary from 1 case per 52 patients years of follow-up to 1 case per 441 patient years of follow-up.