Narrow-band imaging in the diagnosis of early esophageal cancer and precancerous lesions

Background In the recent years, the incidence of esophageal cancer in China has increased. The key point for raising the survival rate is the diagnosis and treatment at an early stage. Narrow-band imaging (NBI) can enhance the contrast of the mucous membrane of the esophagus without staining. This study aimed to explore the value of NBI in the diagnosis of early esophageal cancer and precancerous lesions. Methods The esophagus was examined with ordinary endoscopy and NBI endoscopy. Pit patterns and blood capillary forms were examined with routine magnifying endoscopy and NBI endoscopy. Finally, a 1.2% Lugoul's iodine solution was used to stain the esophageal mucosal surface and a biopsy was taken at all the sites where NBI or iodine staining was positive. NBI and iodine staining scales were compared with pathologic diagnosis, which was considered as the gold standard. Results A total of 90 cases (138 lesions in total) were diagnosed as early esophageal cancer or precancerous lesions; 104 lesions (75.4%) were detected with ordinary endoscopy, 120 lesions (87.0%) were detected with NBI endoscopy, and 138 lesions (100%) were detected with iodine staining. The lesion detection rate of NBI was significantly lower than that of iodine staining (X-2=17.176, P<0.01). However, there was no significant difference between NBI and iodine staining for the diagnosis of high grade intraepithelial neoplasia (X-2=1.362, P>0.05), while the detection rate of NBI was significantly lower than that of iodine staining for the diagnosis of low grade intraepithelial neoplasia (X-2=13.388, P<0.01). The pit pattern and blood capillary form of early esophageal cancer and precancerous lesions could be demonstrated clearer with NBI than with ordinary endoscopy. Conclusions NBI can enhance the contrast of the mucous membrane of the esophagus without staining. The combination of NBI and iodine staining can raise the diagnostic rate of early esophageal cancer and precancerous lesions.