title: Low risk of adenocarcinoma and high-grade dysplasia in patients with non-dysplastic Barrett's esophagus: Results from a cohort from a country with low esophageal adenocarcinoma incidence.
abstract: BACKGROUND
  The risk of esophageal adenocarcinoma (EAC) in non-dysplastic Barrett's esophagus (NDBE) is considered to be approximately 0.3% per year or even lower, according to population-based studies. Data from countries with low EAC incidence are scarce. Our principal aim was to determine the incidence of high-grade dysplasia (HGD) and EAC in NDBE. Our secondary aims were to identify the predictors of progression and to calculate the incidence of HGD/EAC, by using the calculation method for surveillance time in population-based studies.
  
  
  METHODS
  A cohort of NDBE patients was prospectively followed up. Cases of HGD and EAC (study end points) diagnosed during the first year of follow-up were considered as prevalent. Only cases with an endoscopic surveillance time > 1 year were included in our analysis.
  
  
  RESULTS
  We enrolled 331 patients (251 men) in the surveillance program. Their median age was 59 years (interquartile range (IQR): 47-67 years). Their median NDBE length was 3 cm (IQR: 2-4 cm). Of these patients, 80 died during the follow-up (one from EAC) and two were lost to follow-up. After 2284 patient-years of endoscopic follow-up (median surveillance time, 5 years (IQR: 2-10 years)), we found that five cases of HGD and two cases of EAC were diagnosed. The incidence of HGD/EAC was 3.1 cases per 1000 patient-years (95% CI: 1.3-6.0) and that of EAC was 0.9 (95% CI: 0.2-2.9). The incidence of HGD/EAC in short segments (≤ 3 cm) was 0.7 cases per 1000 patient-years (95% CI: 0.3-3.4). The sole variable that we found associated with progression was NDBE length. If the total surveillance time was considered (3537 patient-years), the incidence of HGD and EAC was only slight lower.
  
  
  CONCLUSIONS
  The incidence of HGD and EAC was very low in NDBE. Therefore, current surveillance guidelines must be reassessed, at least for short-segment BE.
authors.affiliation: Department of Gastroenterology, Instituto Português de Oncologia de Lisboa de Francisco Gentil, Lisbon, Portugal; Faculdade de Ciências da Saúde, Universidade da Beira Interior, Covilhã, Portugal.
authors.forename: António Dias
authors.initials: AD
authors.lastname: Pereira
authors.affiliation: Faculdade de Ciências da Saúde, Universidade da Beira Interior, Covilhã, Portugal; Department of Pathology, Instituto Português de Oncologia de Lisboa de Francisco Gentil, Lisbon, Portugal.
authors.forename: Paula
authors.initials: P
authors.lastname: Chaves
keywords: Adenocarcinoma; Barrett’s esophagus; cancer risk; dysplasia; segment length; surveillance