title: The role of tobacco, alcohol, and obesity in neoplastic progression to esophageal adenocarcinoma: a prospective study of Barrett's esophagus.
abstract: BACKGROUND
  Esophageal adenocarcinoma (EA) incidence in many developed countries has increased dramatically over four decades, while survival remains poor. Persons with Barrett's esophagus (BE), who experience substantially elevated EA risk, are typically followed in surveillance involving periodic endoscopy with biopsies, although few progress to EA. No medical, surgical or lifestyle interventions have been proven to safely lower EA risk.
  
  
  METHODS
  We investigated whether smoking, obesity or alcohol could predict progression to EA in a prospective cohort of 411 BE patients. Data were collected during personal interview. Adjusted hazard ratios (HR) were estimated using Cox regression.
  
  
  RESULTS
  39% had body mass index (BMI) over 30 and 64% had smoked cigarettes. Main analyses focused on those with at least 5 months of follow-up (33,635 person-months), in whom 45 developed EA. Risk increased by 3% per year of age (trend p-value 0.02), with approximate doubling of risk among males. EA risk increased with smoking pack-years (trend p-value 0.04) and duration (p-value 0.05). Compared to never-smokers, the HR for those in the highest pack-year tertile was 2.29 (95%CI 1.04-5.07). No association was found with alcohol or BMI, whereas a suggestion of increased risk was observed in those with higher waist-hip ratio, especially among males.
  
  
  CONCLUSIONS
  EA risk significantly increased with increasing age and cigarette exposure. Abdominal obesity, but not BMI, was associated with a modest increased risk. Continued follow-up of this and other cohorts is needed to precisely define these relationships so as to inform risk stratification and preventive interventions.
authors.affiliation: Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America.
authors.forename: Sheetal
authors.initials: S
authors.lastname: Hardikar
authors.forename: Lynn
authors.initials: L
authors.lastname: Onstad
authors.forename: Patricia L
authors.initials: PL
authors.lastname: Blount
authors.forename: Robert D
authors.initials: RD
authors.lastname: Odze
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Reid
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Vaughan
mesh_terms: D000230:Adenocarcinoma / Q000150:complications / Q000175:diagnosis / Q000209:etiology*; D000328:Adult; D000368:Aged; D000428:Alcohol Drinking / Q000009:adverse effects*; D001471:Barrett Esophagus / Q000150:complications / Q000175:diagnosis / Q000209:etiology*; D001706:Biopsy; D015992:Body Mass Index; D018450:Disease Progression; D004938:Esophageal Neoplasms / Q000150:complications / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D014026:Nicotiana