Accuracy of diagnostic demarcation of undifferentiated-type early gastric cancer for magnifying endoscopy with narrow-band imaging: surgical cases

Background and aim The usefulness of magnifying endoscopy with narrow-band imaging (ME-NBI) in undifferentiated-type early gastric cancers (UD-type EGCs) is unclear. This study investigated the accuracy of ME-NBI in the diagnostic demarcation. Methods Among UD-type EGCs that were initially surgically resected between June 2011 and August 2014 in this hospital, 74 lesions were studied that were preoperatively diagnosed with white-light imaging (WLI) or endoscopic ultrasonography as lesions for which endoscopic treatment was not indicated and found to be early gastric cancers by postoperative pathology. The demarcation line was marked on the most oral and anal sides with argon plasma coagulation using WLI and ME-NBI, and the diagnostic demarcation of cancer was defined as correct, if consistent with the results of postoperative pathology. The length of extension into the proliferative zone, distance between crypts and inflammatory cell infiltration (updated Sydney classification: USC) were compared between the correctly diagnosed and the misdiagnosed cases. Results The diagnosis was correct in 62 cases (83.8 %). The average distance between crypts in correctly diagnosed and misdiagnosed cases was approximately 1.9 and 1.3 times, respectively, that in normal mucosa (p < 0.0001). The accuracy of diagnosis was higher when atrophy and neutrophil and monocyte infiltration were mild according to the USC (p < 0.05). The additional use of ME-NBI improved the accuracy of diagnosis by 36.5 % compared with the use of WLI alone. Conclusion The use of ME-NBI in the preoperative diagnosis of the demarcation of cancer is useful to prevent postoperative positive surgical margins.