title: Acetic acid chromoendoscopy for the diagnosis of early neoplasia and specialized intestinal metaplasia in Barrett's esophagus: a meta-analysis.
abstract: OBJECTIVE
  Barrett's esophagus (BE) surveillance with random biopsies is time-consuming, invasive, and can lead to sampling error. Acetic acid chromoendoscopy (AAC) with targeted biopsies has been proposed as an effective alternative. The aim of this study was to assess the diagnostic accuracy of AAC for the detection of early neoplasia (high-grade dysplasia [HGD] or early cancer [EC]) and specialized intestinal metaplasia (SIM) in patients with BE.
  
  
  METHODS
  We performed a meta-analysis of all primary studies that compared AAC-based diagnoses (index test) with histopathology as the reference standard. The data were extracted on a per-patient, per-area, and per-procedure basis whenever available.
  
  
  RESULTS
  Thirteen prospective studies met the inclusion criteria. For the diagnosis of HGD/EC, the pooled sensitivity, specificity, positive likelihood ratio (LR+), and negative likelihood ratio (LR-) for all included studies (9 studies, 1379 patients) were 0.92 (95% confidence interval [CI], 0.83-0.97), 0.96 (95% CI, 0.85-0.99), 25.0 (95% CI, 5.9-105.3), and 0.08 (95% CI, 0.04-0.18), respectively. Results were not significantly different when considering only studies with a per-patient analysis. For the characterization of SIM, the pooled sensitivity, specificity, LR+, and LR- for all the included studies (8 studies, 516 patients) were 0.96 (95% CI, 0.83-0.99), 0.69 (95% CI, 0.54-0.81), 3.0 (95% CI, 2.0-4.7), and 0.06 (95% CI, 0.01-0.26), respectively. No significant sources of heterogeneity were identified on subgroup analysis.
  
  
  CONCLUSIONS
  AAC has an overall high diagnostic accuracy for detecting HGD/EC in patients with BE. For SIM characterization, AAC sensitivity is very high but has poor specificity, suggesting that histological confirmation is necessary when AAC is positive.
authors.affiliation: Gastroenterology and Endoscopy Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy.
authors.forename: Marina
authors.initials: M
authors.lastname: Coletta
authors.affiliation: NIHR Nottingham Digestive Diseases Biomedical Research Unit, Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham, United Kingdom.
authors.forename: Sarmed S
authors.initials: SS
authors.lastname: Sami
authors.affiliation: NIHR Nottingham Digestive Diseases Biomedical Research Unit, Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham, United Kingdom.
authors.forename: Arun
authors.initials: A
authors.lastname: Nachiappan
authors.affiliation: Gastroenterology and Endoscopy Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy.
authors.forename: Mirella
authors.initials: M
authors.lastname: Fraquelli
authors.affiliation: Dipartimento di Scienze Biomediche e Cliniche L. Sacco, Università degli Studi di Milano, Milan, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Casazza
authors.affiliation: NIHR Nottingham Digestive Diseases Biomedical Research Unit, Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham, United Kingdom.
authors.forename: Krish
authors.initials: K
authors.lastname: Ragunath
mesh_terms: D019342:Acetic Acid; D000230:Adenocarcinoma / Q000175:diagnosis* / Q000473:pathology; D001471:Barrett Esophagus / Q000175:diagnosis* / Q000473:pathology; D055088:Early Detection of Cancer; D004938:Esophageal Neoplasms / Q000175:diagnosis* / Q000473:pathology; D004945:Esophagoscopy / Q000379:methods*; D006801:Humans; D007202:Indicators and Reagents; D016013:Likelihood Functions; D060787:Neoplasm Grading; D011237:Predictive Value of Tests
chemical_list: D007202:Indicators and Reagents; D019342:Acetic Acid