New magnifying endoscopic classification for superficial esophageal squamous cell carcinoma

AIM To assess the accuracy of a new magnifying endoscopy(ME)classification for predicting depth of invasion of superficial esophageal squamous cell carcinoma(SESCC).METHODS This study included a total of 70 lesions in 69 patients with SESCC who underwent ME with narrow-band imaging(ME-NBI)before resection from August 2010 to July 2016.Accuracy of ME-NBI for predicting depth of invasion of SESCC was analyzed by using a new ME classification proposed by the Japan Esophageal Society(JES),and interobserver agreement was assessed.RESULTS Overall accuracy of ME-NBI for estimating depth of invasion of SESCC was 78.6%.Sensitivity and specificity of type B1 for tumors limited to the epithelial layer(m1)or invading into the lamina propria(m2)were 71.4%and 100%,respectively.Sensitivity and specificity of type B2 for tumors invading into the muscularis mucosa(m3)or superficial submucosa(≤200μm,sm1)were94.4%and 73.1%,respectively,while those of type B3for tumors invading into the deep submucosa(>200μm,sm2)were 75.0%and 97.8%,respectively.Interobserver agreement was excellent(κ=0.86,95%CI:0.76-0.95).CONCLUSION The recently developed JES ME classification is useful for predicting depth of invasion of SESCC,with reliable interobserver agreement.