May 2007

Document Type


Degree Name



Dept. of Public Health and Preventive Medicine


Oregon Health & Science University


Barrett's esophagus is a known complication of severe GERD, with 8-20% of persons with chronic GERD thought to develop Barrett's. In GERD, the reflux of gastric juice into the esophagus or oropharynx causes symptoms and tissue injury such as ulceration, fibrosis, and esophageal stricture formation. The ulcerated squamous epithelium of the distal esophagus can be replaced by metaplastic, intestinal-type mucosa known as Barrett's esophagus. Consequently, GERD itself is a strong risk factor for esophageal adenocarcinoma20 as well as for its dysplastic precursor Barrett's esophagus. Because up to 20% of the population of the United States experiences weekly symptomatic reflux, the population eligible for endoscopic screening for esophageal adenocarcinoma and Barrett's esophagus is enormous. EGD has not been adopted for screening all patients with symptoms of GERD because of the cost, complexity and risks. Therefore, the American College of Gastroenterology currently recommends that only patients who have "chronic GERD symptoms" be screened for Barrett's screening. Barrett's esophagus, symptomatic gastroesophageal reflux, white ethnicity and male sex are known risk factors for esophageal adenocarcinoma. However, the populations most at risk for esophageal adenocarcinoma remain ill-defined: the majority of patients (>90%) who develop esophageal adenocarcinoma are unaware of the presence of Barrett's esophagus prior to cancer diagnosis.29 This suggests that the majority of patients who are at highest risk for the development of esophageal adenocarcinoma were never screened for Barrett's esophagus. That is, the current screening paradigm has not been adequate in identifying the population most at risk for Barrett's esophagus and esophageal adenocarcinoma. Not only is there still active debate regarding the proper indications for Barrett's screening, but the increasing use of proton pump inhibitors and the growing recognition of atypical GERD symptoms suggests that a better understanding of the Barrett's esophagus in the context of mild GERD could help better define the population of GERD patients to screen. This study examines the relationship between the severity of patients' GERD symptoms and the presence of the esophageal lesions targeted by endoscopic screening: Barrett's esophagus, esophageal dysplasia, and esophageal adenocarcinoma. The nature of their association can offer some insight into these diseases' natural histories and into the subpopulations most at risk for esophageal adenocarcinoma. The study also explores the effect that proton pump inhibitors have on the relationship between GERD symptom severity and Barrett's esophagus or worse, and it considers the risk of Barrett's esophagus or worse associated with esophageal or "typical" versus extraesophageal or "atypical" GERD symptoms.




School of Medicine



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