title: DNA promoter hypermethylation of p16 and APC predicts neoplastic progression in Barrett's esophagus.
abstract: OBJECTIVE
  Prediction of progression to cancer in patients with Barrett's esophagus (BE) is difficult using current techniques. We determined whether DNA promoter hypermethylation of genes frequently methylated in esophageal adenocarcinoma (p16 and APC) could be used as predictors of progression in BE.
  
  
  METHODS
  We first performed a cross-sectional study to evaluate the prevalence of gene hypermethylation in biopsies from patients with normal esophagus (n=17), BE (n=102), and adenocarcinoma (n=42). We then performed a nested case-control study comparing gene hypermethylation in BE patients who progressed from baseline pathology to high-grade dysplasia or cancer (n=7) vs. patients who did not progress (n=50).
  
  
  RESULTS
  None of the patients with normal esophagus had p16 or APC hypermethylation. Hypermethylation was prevalent in BE without dysplasia or low-grade dysplasia (p16=31% and APC=50%; P<0.01) and high-grade dysplasia or adenocarcinoma (p16=54% and APC=68%; P<0.001) compared with normal esophagus (not detected). Patients who progressed from baseline pathology to high-grade dysplasia or cancer had higher prevalence of hypermethylation in their initial esophagus biopsies compared with those who did not progress for both p16 (100 vs. 33%; P=0.008) and APC (86 vs. 40%; P=0.02). Hypermethylation of both p16 and APC was a strong predictor of subsequent progression to high-grade dysplasia or cancer during a mean follow-up time of 4.1 years (odds ratio (95% confidence interval)=14.97 (1.73,inf), P=0.01). Among patients who were negative for both p16 and APC hypermethylation, none progressed from baseline pathology to high-grade dysplasia or cancer.
  
  
  CONCLUSIONS
  Hypermethylation of both p16 and APC strongly predicts progression to high-grade dysplasia or cancer in patients with BE. Absence of p16 and APC hypermethylation is associated with a benign course.
authors: Department of Medicine (Gastroenterology), Johns Hopkins University, Baltimore, Maryland 21287, USA. jeanwang@jhmi.edu
authors: Jean S
authors: JS
authors: Wang
authors: Mingzhou
authors: M
authors: Guo
authors: Elizabeth A
authors: EA
authors: Montgomery
authors: Richard E
authors: RE
authors: Thompson
authors: Hilary
authors: H
authors: Cosby
authors: Lisa
authors: L
authors: Hicks
authors: Shelun
authors: S
authors: Wang
authors: James G
authors: JG
authors: Herman
authors: Marcia I
authors: MI
authors: Canto
mesh_terms: D000230:Adenocarcinoma / Q000209:etiology / Q000503:physiopathology*; D000368:Aged; D001471:Barrett Esophagus / Q000150:complications / Q000503:physiopathology*; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D019175:DNA Methylation; D018450:Disease Progression; D004938:Esophageal Neoplasms / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D017491:Genes, APC / Q000502:physiology*; D019942:Genes, p16 / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011230:Precancerous Conditions / Q000150:complications / Q000503:physiopathology*