 An Opportunity to Generate the Essential Knowledge for Intervention. We have established an initial network of investigators interested in the Barretts Esophagus Study a long term, longitudinal, prospective study and collected preliminary data in patients with BE. To date, 1376 patients from 4 centers have been entered into a central databank. We have presented preliminary data on the incidence and prevalence rates of high-grade dysplasia and cancer at national meetings. We now propose the creation of a formal consortium to perform a cohort study with the ultimate primary aim of defining risk factors for the development of high-grade dysplasia and adenocarcinoma in patients with BE. Such a multi-center, prospective, cohort, multi-disciplinary approach to BE was endorsed by the NIH PRG on stomach and esophageal cancers May 2002. 