Role of targeted biopsy under magnifying endoscopy with narrow band imaging may be not necessary: a prospective diagnostic accuracy study

Targeted biopsy under the guidance of magnifying endoscopy with narrow band imaging (ME-NBI) has higher accuracy than endoscopic forceps biopsy (EFB) in the differential diagnosis of cancerous lesions from noncancerous lesions. The aims of this study were to validate diagnostic efficacy of targeted biopsy under the guidance of ME-NBI (MNTB) and further evaluate whether it is necessary to perform MNTB when combined with ME-NBI.This study prospectively analyzed 211 gastric lesions of suspected cancerous tissues. The sensitivity, specificity, positive predictive value, and negative predictive value of EFB, ME-NBI, MNTB, EFB plus ME-NBI, and MNTB plus ME-NBI for the diagnosis of cancerous lesions were determined, respectively. The accuracy, sensitivity, specificity of EFB and MNTB, EFB plus ME-NBI, and MNTB plus ME-NBI were also compared, respectively.The accuracy, sensitivity, and specificity with 95% confidence intervals were 68.2% (61.4-74.4%), 62.3% (54.1-69.9%), 84.2% (71.6-92.1%) for EFB, 75.4% (68.9-80.9%), 72.7% (64.9-79.4%), 82.5% (69.6-90.8%) for MNTB, 76.8% (70.4-82.2%), 73.4% (65.5-80.0%), 86.0% (73.7-93.3%) for ME-NBI, 82.0% (76.0-86.8%), 85.7% (79.0-90.6%), 71.9% (58.3-82.6%) for EFB plus ME-NBI, 84.8% (79.1-89.3%), 89.6% (83.4-93.8%), and 71.9% (58.3-82.6%) for MNTB plus ME-NBI, respectively. The sensitivity of MNTB was significantly higher than that of EFB (P=0.048). There was no significant difference in the sensitivity (P=0.307), specificity (P=1.000), and accuracy (P=0.337) between EFB plus ME-NBI and MNTB plus ME-NBI.Although MNTB has a higher diagnostic efficacy than EFB in the diagnosis of cancerous lesions, it may be not necessary to perform MNTB when combined with ME-NBI.