title: Narrow-band imaging endoscopy with magnification is useful for detecting metachronous superficial pharyngeal cancer in patients with esophageal squamous cell carcinoma.
abstract: OBJECTIVE
  Head and neck cancers, especially pharyngeal cancers, as well as esophageal cancers frequently coexist either synchronously or metachronously, but most cases of pharyngeal cancer are detected at an advanced stage resulting in poor prognosis. The aim of this study is to evaluate the effectiveness of using narrow-band imaging (NBI) endoscopy with magnification for early detection of pharyngeal cancer on patients following their treatment for esophageal squamous cell carcinoma (SCC).
  
  
  METHODS
  This case series was conducted at the National Cancer Center Hospital in Tokyo between April and October 2005 and included 424 consecutive patients for surveillance endoscopy who had previously undergone chemoradiotherapy (CRT) and/or surgery for esophageal SCC. Observation of the pharyngeal region was randomly conducted on 91 patients using NBI endoscopy with magnification (NBI group) and 333 patients using conventional white light endoscopy (control group).
  
  
  RESULTS
  The detection rate for pharyngeal cancer was significantly higher using NBI endoscopy with magnification (10.9%; 10/91) compared with conventional endoscopy (1.2%; 4/333) (P < 0.0001). In particular, the detection rate in CRT patients was significantly higher in the NBI group (12.9%; 7/54) than the control group (0.5%; 1/191) (P < 0.0001). In addition, diagnostic sensitivity, specificity, accuracy, positive predictive value and negative predictive value for the NBI group were 100% (10/10), 97.5% (79/81), 97.8% (89/91), 83.3% (10/12) and 100% (79/79), respectively.
  
  
  CONCLUSIONS
  NBI endoscopy with magnification is a promising technique for detecting superficial pharyngeal cancer at an early stage in patients previously treated for esophageal SCC.
authors.affiliation: Endoscopy Division, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Nonaka
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Saito
authors.forename: Ichiro
authors.initials: I
authors.lastname: Oda
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kozu
authors.forename: Daizo
authors.initials: D
authors.lastname: Saito
mesh_terms: D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000628:therapy*; D016022:Case-Control Studies; D055088:Early Detection of Cancer; D016145:Endoscopy, Digestive System / Q000379:methods*; D004938:Esophageal Neoplasms / Q000473:pathology / Q000628:therapy*; D004945:Esophagoscopy / Q000379:methods; D005260:Female; D006801:Humans; D007089:Image Enhancement; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D016609:Neoplasms, Second Primary; D010610:Pharyngeal Neoplasms / Q000473:pathology*; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D014041:Tokyo