title: Narrow band imaging versus lugol chromoendoscopy to diagnose squamous cell carcinoma of the esophagus: a systematic review and meta-analysis.
abstract: In the early stage esophageal cancer, changes in the mucosa are subtle and pass unnoticed in endoscopic examinations using white light. To increase sensitivity, chromoscopy with Lugol's solution has been used. Technological advancements have led to the emergence of virtual methods of endoscopic chromoscopy, including narrow band imaging (NBI). NBI enhances the relief of the mucosa and the underlying vascular pattern, providing greater convenience without the risks inherent to the use of vital dye. The purpose of this systematic review and meta-analysis was to evaluate the ability of NBI to diagnose squamous cell carcinoma of the esophagus and to compare it to chromoscopy with Lugol's solution.
  
  
  
  This systematic review included all studies comparing the diagnostic accuracy of NBI and Lugol chromoendoscopy performed to identify high-grade dysplasia and/or squamous cell carcinoma in the esophagus. In the meta-analysis, we calculated and demonstrated sensitivity, specificity, and positive and negative likelihood values in forest plots. We also determined summary receiver operating characteristic (sROC) curves and estimates of the areas under the curves for both per-patient and per-lesion analysis.
  
  
  
  The initial search identified 7079 articles. Of these, 18 studies were included in the systematic review and 12 were used in the meta-analysis, for a total of 1911 patients. In per-patient and per-lesion analysis, the sensitivity, specificity, and positive and negative likelihood values for Lugol chromoendoscopy were 92% and 98, 82 and 37%, 5.42 and 1.4, and 0.13 and 0.39, respectively, and for NBI were 88 and 94%, 88 and 65%, 8.32 and 2.62, and 0.16 and 0.12, respectively. There was a statistically significant difference in only specificity values, in which case NBI was superior to Lugol chromoendoscopy in both analyses. In the per-patient analysis, the area under the sROC curve for Lugol chromoendoscopy was 0.9559. In the case of NBI, this value was 0.9611; in the per-lesion analysis, this number was 0.9685 and 0.9587, respectively.
  
  
  
  NBI was adequate in evaluating the esophagus in order to diagnose high-grade dysplasia and squamous cell carcinoma. In the differentiation of those disorders from other esophageal mucosa alterations, the NBI was shown to be superior than Lugol.
authors.affiliation: Gastrointestinal Endoscopy at University of Sao Paulo, Rua Capote Valente n 671, Pinheiros, São Paulo, Zipcode 05409-002, Brazil. flaviomorita@hotmail.com.
authors.forename: Flavio Hiroshi Ananias
authors.identifier: 0000-0002-2464-1713
authors.initials: FH
authors.lastname: Morita
authors.affiliation: University of Sao Paulo, Rua Maria Vidal 124, Perdizes, São Paulo, SP, CEP 01253-040, Brazil.
authors.forename: Wanderley Marques
authors.initials: WM
authors.lastname: Bernardo
authors.affiliation: Gastrointestinal Endoscopy at University of Sao Paulo, Rua Cristiano Viana 647 apto 141, Pinheiros, São Paulo, SP, CEP 05411-001, Brazil.
authors.forename: Edson
authors.initials: E
authors.lastname: Ide
authors.affiliation: Gastrointestinal Endoscopy at University of Sao Paulo, Alameda Ministro Rocha Azevedo 373, Cerqueira Cesar, São Paulo, SP, CEP 01410-001, Brazil.
authors.forename: Rodrigo Silva Paula
authors.initials: RS
authors.lastname: Rocha
authors.affiliation: Gastrointestinal Endoscopy at University of Sao Paulo, Rua Teodoro Sampaio 498 apto 33, Pinheiros, São Paulo, SP, CEP 05405-000, Brazil.
authors.forename: Julio Cesar Martins
authors.initials: JC
authors.lastname: Aquino
authors.affiliation: Gastrointestinal Endoscopy at University of Sao Paulo, Rua Cardoso de Almeida 840, Perdizes, São Paulo, SP, CEP 05013-001, Brazil.
authors.forename: Mauricio Kazuyoshi
authors.initials: MK
authors.lastname: Minata
authors.affiliation: Gastrointestinal Endoscopy at University of Sao Paulo, Rua Malebranche 99 apto 142, Chácara Klabin, São Paulo, SP, CEP 04116-160, Brazil.
authors.forename: Kendi
authors.initials: K
authors.lastname: Yamazaki
authors.affiliation: Gastrointestinal Endoscopy at University of Sao Paulo, Avenida Libero Badoro 451, Bairro Jardim São Caetano, São Caetano do Sul, SP, CEP 09581-610, Brazil.
authors.forename: Sergio Barbosa
authors.initials: SB
authors.lastname: Marques
authors.affiliation: Gastrointestinal Endoscopy at University of Sao Paulo, Rua Sincinato Braga 3712, Paraiso, São Paulo, SP, CEP 01323-011, Brazil.
authors.forename: Paulo
authors.initials: P
authors.lastname: Sakai
authors.affiliation: Gastrointestinal Endoscopy at University of Sao Paulo, Avenida Dr. Enéas de Carvalho Aguiar 255, sexto andar, bloco 3, Pinheiros, São Paulo, SP, CEP 05403-000, Brazil.
authors.forename: Eduardo Guimarães Hourneaux
authors.initials: EG
authors.lastname: de Moura
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000473:pathology*; D003430:Cross-Sectional Studies; D004938:Esophageal Neoplasms / Q000175:diagnosis* / Q000473:pathology*; D004945:Esophagoscopy / Q000379:methods*; D004947:Esophagus / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D062048:Narrow Band Imaging / Q000379:methods*; D011446:Prospective Studies; D012372:ROC Curve; D016032:Randomized Controlled Trials as Topic; D012680:Sensitivity and Specificity
keywords: Esophageal neoplasm; Esophageal scquamous cell carcinoma; Lugol chromoendoscopy; Narrow band imaging