BACKGROUND/AIMS: Iodine staining of the esophagus has been shown to be useful in detecting esophageal cancer. Narrow band imaging (NBI), a new endoscopic lighting system, visualizes the microvasculature of the gastrointestinal (GI) mucosa. To evaluate the detectability of early esophageal cancer by screening endoscopy assisted with NBI as compared with that assisted with iodine staining. DESIGN: A prospective comparative study. Setting A single endoscopy unit. PATIENTS: Forty-nine consecutive patients, consisting of 40 males and 9 females with a mean age of 67, most of whom were at high risks for esophageal cancer (heavy drinker and smoker, history of cancer especially of head and neck, etc.). INTERVENTION: Following conventional endoscopic observation, the esophagus was observed with NBI for possible cancerous lesions. Dark-brown areas on NBI were defined as NBI-positive areas. Esophageal mucosa was subsequently stained with 1.5% iodine, and both findings were compared. Finally, the areas discolored by iodine stain were biopsied for histological evaluation. MAIN OUTCOME MEASUREMENTS: The sensitivity, specificity, and positive predictive value (PPV) of endoscopic detection of esophageal cancer. RESULTS: Squamous cell carcinoma was detected in 5 out of 118 areas. Esophageal cancers detected were all both NBI-positive and discolored by iodine staining. Sensitivity, specificity, and PPV of NBI-positive areas for cancer were 100%, 59%, and 9.8%, respectively. On the other hand, the discolored areas with iodine staining for cancer were 100%, 4.4%, and 4.4%, respectively. NBI observation was significantly superior to iodine staining for detecting esophageal cancer (p < 0.02). LIMITATION: In this study, the endoscopist engaged was not blinded and the assessment was not standardized. CONCLUSIONS: Esophageal endoscopy assisted with NBI was more useful for detecting early esophageal cancer than that assisted with iodine staining.
BACKGROUND/AIMS: Iodine staining of the esophagus has been shown to be useful in detecting esophageal cancer. Narrow band imaging (NBI), a new endoscopic lighting system, visualizes the microvasculature of the gastrointestinal (GI) mucosa. To evaluate the detectability of early esophageal cancer by screening endoscopy assisted with NBI as compared with that assisted with iodine staining. DESIGN: A prospective comparative study. Setting A single endoscopy unit. PATIENTS: Forty-nine consecutive patients, consisting of 40 males and 9 females with a mean age of 67, most of whom were at high risks for esophageal cancer (heavy drinker and smoker, history of cancer especially of head and neck, etc.). INTERVENTION: Following conventional endoscopic observation, the esophagus was observed with NBI for possible cancerous lesions. Dark-brown areas on NBI were defined as NBI-positive areas. Esophageal mucosa was subsequently stained with 1.5% iodine, and both findings were compared. Finally, the areas discolored by iodine stain were biopsied for histological evaluation. MAIN OUTCOME MEASUREMENTS: The sensitivity, specificity, and positive predictive value (PPV) of endoscopic detection of esophageal cancer. RESULTS:Squamous cell carcinoma was detected in 5 out of 118 areas. Esophageal cancers detected were all both NBI-positive and discolored by iodine staining. Sensitivity, specificity, and PPV of NBI-positive areas for cancer were 100%, 59%, and 9.8%, respectively. On the other hand, the discolored areas with iodine staining for cancer were 100%, 4.4%, and 4.4%, respectively. NBI observation was significantly superior to iodine staining for detecting esophageal cancer (p < 0.02). LIMITATION: In this study, the endoscopist engaged was not blinded and the assessment was not standardized. CONCLUSIONS: Esophageal endoscopy assisted with NBI was more useful for detecting early esophageal cancer than that assisted with iodine staining.