Magnifying endoscopy with narrow-band imaging for early gastric cancer diagnosis

Abstract

Objective To evaluate magnifying endoscopy combined with narrow-band imaging （ ME- NBI） for diagnosis of early gastric cancer （EGC）. Methods A total of 150 focal lesions from 143 patients over 35 years old identified by white light endoscopy （WLE） from March 2010 to December 2010 in our tertiary referential institution were recruited in the prospective study with written informed consent. Focal lesions were defined as any small local mucosa with abnormal shape or color based on an assessment of findings of WLE without any specified criteria, including superficial, depressed and elevated lesions. The patients with local advanced gastric cancer, submucosal lesions and history of gastrectomy were excluded from the study. All the patients received ME-NBI. Based on literature, national criteria of early diagnosis with ME- NBI were established. All the lesions underwent biopsy and pathological examination. Diagnostic accuracy of ME-NBI for EGC was assessed with reference to histopathology. Results In 150 focal lesions, 19 were pathologically diagnosed as EGC, 8 of which were treated by endoscopic resection and 11 were resected surgically. The sensitivity, specificity, positive predictive value （pPV）, negative predictive value （NPV） and accuracy of conventional WLE for diagnosing EGC were 94. 7%, 53.4%, 22. 8%, 98.6% and 58.7%, respectively. The counterparts of ME-NBI for diagnosing EGC were 73.7%, 99. 2%, 93.3% , 96. 3% and 96. 0%, respectively. The diagnostic accuracy of ME-NBI was significantly better than that of conventional WLE （96.0% vs. 58. 7%, P 〈0.05）. With regard to the findings of EGC on ME-NBI, irregular or absent microsurface pattern and mierovascular pattern were characteristic features of EGC. Conclusion Conventional WLE is still an important and mandatory screening modality, which is significant for further procedures of suspected lesions, preferably accompanied with biopsy. ME-NBI achieved superior accuracy in the differential diagnosis of focal lesions detected with conventional WLE, but needs further verification. Key words: Early diagnosis; Stomach neoplasms; Magnifying endoscopy; Narrow-band imaging