Endoscopic Detection of Dysplasia in Barrett's Esophagus
Condition: Barrett's Esophagus
MeSH terms: Barrett Esophagus
Study type: Interventional

Summary: 
      The purpose of this study is to determine whether High Resolution Magnification Endoscopy
      (HRME) and Computed Virtual Chromoendoscopy (CVC) with targeted biopsies is superior to
      conventional white light endoscopy (WLE) with 4 quadrant biopsies of the metaplastic
      epithelium every 1-2 cm (Seattle Protocol) for detection of pre-malignant lesions in patients
      with Barrett's Esophagus (BE).
    

Detailed description: 
      BE is a metaplastic mucosal transformation adjacent to the esophagogastric junction, due to
      chronic reflux of gastric juices, Gastro Esophageal Reflux Disease (GERD). The continuous
      esophageal exposure of acid- and/or bile- containing fluids leads, untreated, to chronic
      esophagitis. In certain patients a mucosal transformation takes place. The epithelium in the
      distal part of esophagus is transferred from squamous into a more intestinal-like mucosa,
      called Specialized Intestinal Metaplasia (SIM).Patients with BE is believed to run a higher
      risk of developing esophageal adenocarcinoma (EAC).

      EAC is a rare condition in the western society, but the prevalence is rising compared with
      other malignancies, and a substantial increase has been seen during the last four decades.
      The pathogenesis of cancer development is believed to be that SIM in some patients can
      undergo dysplastic transformation, from low to high grade, and from high grade dysplasia
      (HGD) develop into AC. Advanced EAC is associated to a poor prognosis whereas HGD or
      carcinoma in situ may be treated endoscopically with a favorable outcome.

      The need for surveillance endoscopy in order to discover early cancer lesions available to
      curable treatment is up against cost effectiveness and evidence level regarding screening.
      The conventional endoscopic (CE) surveillance algorithm for BE is standard WLE and 4 quadrant
      biopsies of the metaplastic epithelium every 1-2 cm above the esophagogastric junction. The
      development of advanced endoscopic techniques have made it possible to distinguish minimal
      polypoid lesions but also the microvasculature and pit-pattern structures that in certain
      grading systems have been associated to presence of dysplasia. Attempts have been made in
      exploring the benefits of advanced endoscopic technologies against standard WLE.
      Feasibility-studies suggests that the new techniques improves the biopsy-yield for dysplasia,
      however only a limited number of prospective studies exist.

      Study aim: To determine whether HRME and CVC with targeted biopsies is superior to
      conventional WLE with 4 quadrant biopsies of the metaplastic epithelium every 1-2 cm (Seattle
      Protocol) for detection of pre-malignant lesions in patients with BE.

      Primary endpoint: Incidence of detected dysplasia by each endoscopic technique. Secondary
      endpoints: 1.The yield of low- and/or high-grade dysplasia by each endoscopic technique.
      2.The number of biopsies taken and the duration of the different endoscopic techniques. 3.The
      endoscopic prediction capability of present dysplasia compared to histopathology for HRME.

      Statistical power: Based on the primary endpoint, the amount of dysplasia in a
      Barrett-population is approximately 10%. We calculated a raise in positive yield with using
      advanced endoscopy to 8%. At p<0,05 and a power of 80% the need for 105 patients.

      Setting: Tertiary referral high volume endoscopy center at Sahlgrenska University Hospital,
      Sweden.
    

Intervention name(s): HRME+CVC; conventional endoscopy
Intervention type(s): Procedure; Procedure
Intervention description(s): High resolution magnification endoscopy with computed virtual chromoendoscopy and directed biopsy; Conventional white light endoscopy with four-quadrant biopsy
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Single (Investigator)
Primary purpose: Diagnostic
Keywords: Endoscopy, Gastrointestinal