Gastroesophageal reflux, barrett esophagus, and esophageal cancer: scientific review.

摘要

CONTEXT: Gastroesophageal reflux disease (GERD) is a risk factor for adenocarcinoma of the esophagus, a rare cancer whose incidence is increasing. Adenocarcinoma may develop from Barrett esophagus, a metaplastic change of the esophageal epithelium from squamous to intestinalized columnar mucosa, which is associated with chronic reflux. Some have recommended that patients with chronic reflux symptoms undergo upper endoscopy to assess for Barrett esophagus and to screen for cancer. OBJECTIVES: To review the evidence linking GERD and Barrett esophagus to esophageal adenocarcinoma and to examine the utility of upper endoscopy as a screening tool in adenocarcinoma of the esophagus among individuals with GERD. DATA SOURCES: A MEDLINE search was performed to identify all pertinent English-language reports about GERD, adenocarcinoma, and Barrett esophagus from 1968 through 2001. Reports were of randomized controlled clinical trials if available, case-control data if trials were unavailable, and cohort studies if case-control data were unavailable. Pertinent bibliographies were also reviewed to find reports not otherwise identified. STUDY SELECTION AND DATA EXTRACTION: Studies were selected by using the search terms gastroesophageal reflux, adenocarcinoma, and Barrett's esophagus, with subheadings for classification, complications, drug therapy, economics, epidemiology, mortality, surgery, and prevention and control. Clinical guidelines for the care of subjects with GERD and Barrett esophagus were retrieved and abstracted. DATA SYNTHESIS: Cohort studies demonstrate that symptoms of GERD occur monthly in almost 50% of US adults and weekly in almost 20%. Three large case-control studies demonstrate a positive association between reflux symptoms and risk of adenocarcinoma of the esophagus, with more prolonged and severe symptoms accentuating this risk. However, because of the low incidence of adenocarcinoma of the esophagus and the ubiquity of reflux symptoms, the risk of cancer in any given individual with reflux symptoms is low. No randomized trial data are available to demonstrate either decreased cancer incidence or increased life expectancy in subjects with GERD who undergo screening endoscopy. CONCLUSIONS: Strong evidence supports the association of GERD and adenocarcinoma of the esophagus; however, the risk of cancer in any given individual with GERD is low. Barrett esophagus appears to be a common precursor lesion to this cancer. Given the low absolute risk of cancer in those with GERD and the lack of demonstrated efficacy of endoscopic screening, insufficient evidence exists to endorse routine endoscopic screening of patients with chronic GERD symptoms.