Symptoms of gastroesophageal reflux are common. It affects at least 40% of the adult American population and 40 million American adults experience reflux symptoms on a regular basis. Gastroesophageal reflux disease (GERD) typically affects Caucasians and older males. It is a significant risk factor for development of Barrett's esophagus (BE) and esophageal adenocarcinoma. Approximately 10-15% of patients with chronic GERD are diagnosed with BE, a premalignant lesion for esophageal adenocarcinoma. Adenocarcinoma of the esophagus continues to be the most rapidly increasing incidence cancer in the United States. Based on studies evaluating screening/surveillance strategies, it is clear that it is imperative to identify risk factors that would target those patients with gastroesophageal reflux disease (GERD) and BE that may benefit from screening and surveillance strategies, yet also be practical and cost-effective. A better understanding of the events surrounding the development of BE in patients with chronic GERD, development of dysplastic changes in patients with BE and progression of BE to adenocarcinoma may ultimately help in identifying those patients at increased risk. Thus, our hypothesis is that systematic collection of data on the natural history of GERD and BE patients and risk factors for development of BE in patients with chronic GERD and progression of BE to dysplasia and adenocarcinoma will provide useful information to develop a decision model for risk stratification and risk reduction strategies in these patients. This model will be a useful tool leading to a reduction in overall health care costs.