Is there a relationship between the length of Barrett's esophagus and the presence or degree of dysplasia?
S.R. Hamilton (Baltimore)
Endoscopic surveillance for early detection and/or prophylactic treatment of adenocarcinoma and epithelial dysplasia in columnar-lined mucosa of the esophagus and esophagogastric junction region represents a potential strategy for reducing the rising incidence of adenocarcinoma. The relationship between the development of dysplasia and the length of columnar-lined mucosa has important implications for patient selection in this strategy. Essentially no data on the natural history of the columnar epithelial dysplasia-adenocarcinoma sequence from large series of patients have been reported, so that the incidences in patients with various lengths of Barrett's mucosa are currently unknown. Furthermore, little data on prevalence relative to length of Barrett's mucosa have been reported in the literature. Nevertheless, long segments of columnar-lined mucosa would be expected to be at higher risk for the development of dysplasia and for its progression to more severe dysplasia because of the stochastic nature of the neoplastic process: the more cells at risk, the higher the expected occurrence.
Adenocarcinoma is well known to occur in short segments of Barrett's mucosa [1, 2]. The majority of adenocarcinomas occur in relatively short segments because the occurrence of short segments is more frequent, but existing reports for adenocarcinoma and columnar epithelial dysplasia support higher risk in patients with long segments than in those with short segments (Table I).
Only one study addressed the severity of dysplasia and found an increased prevalence of moderate and high-grade dysplasia in long segments: 9/82 (11%) patients with long segments had moderate or high-grade dysplasia as compared with 0/121 with a short segment (p = .0002) .
Prospective endoscopic studies of the surface area of columnar-lined mucosa, in addition to the length alone, are needed to provide more complete data upon which decisions about patient management can be based. Such data are likely to be used in cost-benefit/cost-effectiveness analysis to address patient selection for surveillance. The spectrum of the natural history of the development of neoplasia in columnar-lined regions will then become more evident. In addition, ablative therapy directed at Barrett mucosa is predicated in part on the assumption that reducing the extent of columnar-lined mucosa will reduce the occurrence of neoplasia. Long-term follow-up studies after ablation by various techniques are needed.
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