Pharyngeal cancer surveillance using narrow band imaging during conventional upper gastrointestinal endoscopy.

Background: Recent studies have suggested that narrow band imaging (NBI) is useful for detecting superficial pharyngeal cancer. Nevertheless, pharyngeal observation is not a routine practice during upper gastrointestinal (GI) endoscopy. Two aims of this study were to evaluate the feasibility of pharyngeal observation during upper GI endoscopy and to determine the prevalence of pharyngeal cancer in asymptomatic high-risk patients.