title: Erosive reflux disease increases risk for esophageal adenocarcinoma, compared with nonerosive reflux.
abstract: OBJECTIVE
  Gastroesophageal reflux disease is a strong risk factor for esophageal adenocarcinoma, but it is not clear whether the mucosal inflammation that develops in patients with reflux disease promotes this cancer. We determined the development of adenocarcinoma among patients who underwent esophagogastroduodenoscopy and were found to have erosive (with esophagitis) or nonerosive (without esophagitis) reflux.
  
  
  METHODS
  We performed a nationwide cohort study using data from 33,849 patients with reflux disease (52% men; median age, 59.3 y) from population-based Danish medical registries, from 1996 through 2008. The observed incidences of adenocarcinoma were compared with the expected incidence for the general population, standardized by age, sex, and calendar time. Absolute risks were estimated using Kaplan-Meier methods.
  
  
  RESULTS
  In the study cohort, 26,194 of the patients (77%) had erosive reflux disease and 37 subsequently developed esophageal adenocarcinoma after a mean follow-up time of 7.4 years. Their absolute risk after 10 years was 0.24% (95% confidence interval [CI], 0.15%-0.32%). The incidence of cancer among patients with erosive reflux disease was significantly greater than that expected for the general population (standardized incidence ratio, 2.2; 95% CI, 1.6-3.0). In contrast, of the 7655 patients with nonerosive reflux disease, only 1 was diagnosed with esophageal adenocarcinoma after 4.5 years of follow-up evaluation (standardized incidence ratio, 0.3; 95% CI, 0.01-1.5).
  
  
  CONCLUSIONS
  Erosive reflux disease, but not nonerosive disease, increased the risk of esophageal adenocarcinoma, based on analysis of population-based Danish medical registries. Inflammation therefore might be an important factor in the progression from reflux to esophageal adenocarcinoma.
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus N, Denmark. re@dce.au.dk
authors.forename: Rune
authors.initials: R
authors.lastname: Erichsen
authors.forename: Douglas
authors.initials: D
authors.lastname: Robertson
authors.forename: Dora K
authors.initials: DK
authors.lastname: Farkas
authors.forename: Lars
authors.initials: L
authors.lastname: Pedersen
authors.forename: Heiko
authors.initials: H
authors.lastname: Pohl
authors.forename: John A
authors.initials: JA
authors.lastname: Baron
authors.forename: Henrik T
authors.initials: HT
authors.lastname: Sørensen
mesh_terms: D000230:Adenocarcinoma / Q000453:epidemiology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D016145:Endoscopy, Digestive System; D004938:Esophageal Neoplasms / Q000453:epidemiology*; D005260:Female; D005764:Gastroesophageal Reflux / Q000150:complications* / Q000473:pathology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment