title: Low-grade dysplasia in Barrett's esophagus has a high risk of progression.
abstract: OBJECTIVE
  Surveillance in Barrett's esophagus relies on the detection of dysplasia by histopathology. However, the natural history of this condition, particularly that of low-grade dysplasia (LGD) is poorly understood. This paper describes our experience of LGD over a period of 21 years.
  
  
  METHODS
  Between 1984 and January 1995, 357 patients with Barrett's esophagus without dysplasia were recruited for annual surveillance: 34 of these patients developed LGD during this period. This was a retrospective cohort study of this group in terms of survival and cancer outcomes >/= 8 years after the original diagnosis of LGD, comparing them with the patients who did not develop LGD over the same period, with a histopathological review of the original diagnoses of LGD. The outcomes of 356/357 (99.7 %) of the patients were established in December 2004.
  
  
  RESULTS
  After 8 years, high-grade dysplasia (HGD) or cancer had developed in 9/34 patients with LGD (27 %) and in 16/322 controls (5 %). Cox's proportional hazards model revealed that the time from the first diagnosis of Barrett's esophagus to the first "event" of either HGD, esophageal cancer, or death did not show a statistically significant difference between the two groups. A further analysis treating death as "loss to follow-up" showed a significantly increased risk for the LGD group to progress to HGD or cancer (hazard ratio 5.9 [95 % confidence interval 2.6 - 13.4], P< 0.001). The histopathology review demonstrated a fair level of agreement between pathologists, with a kappa value of 0.48.
  
  
  CONCLUSIONS
  Patients diagnosed with LGD during surveillance of Barrett's esophagus are at a considerably increased risk of progressing to develop esophageal cancer over an 8-year period but most deaths are not cancer-related.
authors.affiliation: Department of Gastroenterology, Good Hope Hospital, Sutton Coldfield, United Kingdom. Chee.Lim@heartofengland.nhs.uk
authors.forename: C H
authors.initials: CH
authors.lastname: Lim
authors.forename: D
authors.initials: D
authors.lastname: Treanor
authors.forename: M F
authors.initials: MF
authors.lastname: Dixon
authors.forename: A T R
authors.initials: AT
authors.lastname: Axon
mesh_terms: D000368:Aged; D001471:Barrett Esophagus / Q000150:complications / Q000473:pathology*; D018450:Disease Progression; D004938:Esophageal Neoplasms / Q000209:etiology* / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D013997:Time Factors