Diagnostic accuracy of demarcation of undifferentiated-type early gastric cancer after Helicobacter pylori eradication.

BACKGROUND: It is unknown whether Helicobacter pylori (H. pylori) eradication is beneficial when demarcating undifferentiated-type early gastric cancers (UD-type EGCs). This study aimed to determine whether H. pylori eradication is beneficial, and also when benefits become detectable.

METHODS: Sixty lesions that were detected as a ≤20-mm lesion without metastasis or ulceration on routine examination, diagnosed as UD-type EGC on biopsy, and treated with endoscopic submucosal dissection between January 2010 and January 2015 were studied. Magnifying endoscopy with narrow-band imaging (ME-NBI) was performed to demarcate the lesions. The most oral and most anal sites were marked. After endoscopic therapy, the markings were compared with the pathological examination results to calculate accurate diagnosis rates, which were compared between 27 patients with H. pylori eradication and 33 patients without. Mean intercrypt distance ratio and inflammatory cell infiltration were also compared, as were seven patients who underwent the procedure 1 month after H. pylori eradication and 20 patients who underwent the procedure more than 1 month after H. pylori eradication.

RESULTS: Accurate diagnosis rates were 92.2% with eradication and 60.6% without. Mean intercrypt distance ratios were 1.95 and 1.59, respectively. Neutrophil infiltration was mild in the eradication group. Significant differences were observed in each parameter (p < 0.05). No significant difference was observed between the 1-month eradication and >1-month eradication subgroups in terms of accurate diagnosis rate, mean intercrypt distance ratio, or histological grade of any item.

CONCLUSIONS: This study suggests that H. pylori eradication therapy aids the accurate delineation of UD-type EGC in ME-NBI.