BE is strongly neovascularized not eroded. This novel concept of a molecular mechanism of the origin of BE might emphasize why precancerous BE can give rise to the more cancerous dysplasia and Barrett's adenocarcinoma stages. In addition, adenocarcinoma cells induce lymphangiogenesis. The new lymphangiogenic vessels might provide a systemic route for adenocarcinoma cells to invade circulation and induce lymph node metastasis.

Mechanisms underlying the development of oesophageal adenocarcinoma are poorly understood. To discover the role of oxidative stress and radical scavenger capacity in the malignant transformation of Barrett's oesophagus, we measured myeloperoxidase activity, superoxide dismutase activity, glutathione content and total aromatic DNA adducts. Mucosal specimens came from 52 patients in 6 groups: symptomatic gastro-oesophageal reflux disease (GORD) without and with endoscopic oesophagitis, Barrett's epithelium without and with dysplasia, adenocarcinoma in the oesophagus and controls. In the GORD-oesophagitis-metaplasia-dysplasia-adenocarcinoma sequence, glutathione content was progressively lower and myeloperoxidase activity higher than in controls, plateauing at Barrett's epithelium without dysplasia. Only in Barrett's epithelium with dysplasia was SOD activity significantly increased. In all patient groups, DNA adduct levels were significantly higher than the control level. Though these levels between patient groups did not differ significantly, the level was highest in Barrett's epithelium without dysplasia and progressively lower in Barrett's with dysplasia and adenocarcinoma. Pooled data showed a negative correlation between glutathione content and DNA adducts (؊0.28, p ‫؍‬ 0.05). Simultaneous formation of DNA adducts, increased myeloperoxidase-related oxidative stress, decreased antioxidant capacity (glutathione content) and the negative correlation between glutathione content and DNA adducts in the GORD-oesophagitis-metaplasia-dysplasiaadenocarcinoma sequence of Barrett's oesophagus indicate a role in the pathogenesis and malignant transformation related to oxidative stress.

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ObjectiveThe regeneration of intestinal metaplasia by squamous epithelium in 17 patients with Barrett's esophagus after endoscopic laser ablation in a reflux-free environment after successful antireflux surgery was prospectively examined.