The excellent long-term outcome of gastric MALT lymphoma after H pylori eradication was confirmed by this large-scale follow-up study.

For first eradication in patients allergic to penicillin, a 7-day triple therapy consisting of clarithromycin, metronidazole and vonoprazan could be a candidate eradication regimen.

ESD was slower for sigmoid colon tumors than for tumors in other areas, suggesting that ESD was technically more difficult in the sigmoid colon than in other colorectal areas. Submucosal fibrosis was independently associated with perforation during colorectal ESD.

Background: The definition of Helicobacter pylori-negative gastric cancer depends on the accuracy of diagnosis of H. pylori infection. The aim of this study was to determine the frequency of H. pylori-negative gastric cancer and to clarify relationships with histological atrophy, endoscopic atrophy, and serological atrophy. Methods: A total of 240 early gastric cancers were included in this study. The status of H. pylori infection was determined from the rapid urease test, ¹³C-urea breath test, H. pylori culture, histopathological examination and examination of IgG antibodies. In H. pylori-negative gastric cancer, histological atrophy and intestinal metaplasia, endoscopic atrophy and serological atrophy were assessed by pepsinogen. Results: The rate of H. pylori infection was 77.9% and 19 patients (7.9%) had a history of eradication. 34 patients (14.2%) were diagnosed with H. pylori-negative gastric cancer using diagnostic tools of H. pylori. However, most of the patients with H. pylori-negative gastric cancer had histological atrophy and intestinal metaplasia. Only 1 gastric cancer (0.42%) occurred in the mucosa without histological atrophy, endoscopic atrophy or serological atrophy. Conclusion: Early gastric cancers in the Japanese endoscopic submucosal dissection series were strongly related to current or past infection with H. pylori and to gastric mucosal atrophy.

ObjectivesEvaluation of Helicobacter pylori infection status (non‐infection, past infection, current infection) has become important. This study aimed to determine the usefulness of the Kyoto classification of gastritis for diagnosing H. pylori infection status by endoscopy.MethodsIn this prospective study, 498 subjects were recruited. Seven well‐experienced endoscopists blinded to the history of eradication therapy performed the examinations. Endoscopic findings were assessed according to the Kyoto classification of gastritis: diffuse redness, regular arrangement of collecting venules (RAC), fundic gland polyp (FGP), atrophy, xanthoma, hyperplastic polyp, map‐like redness, intestinal metaplasia, nodularity, mucosal swelling, white and flat elevated lesion, sticky mucus, depressive erosion, raised erosion, red streak, and enlarged folds. We established prediction models according to a machine learning procedure and compared them with general assessment by endoscopists using the Kyoto classification of gastritis.ResultsSignificantly higher diagnostic odds were obtained for RAC (32.2), FGP (7.7), and red streak (4.7) in subjects with non‐infection, map‐like redness (12.9) in subjects with past infection, and diffuse redness (26.8), mucosal swelling (13.3), sticky mucus (10.2) and enlarged fold (8.6) in subjects with current infection. The overall diagnostic accuracy rate was 82.9% with the Kyoto classification of gastritis. The diagnostic accuracy of the prediction model was 88.6% for the model without H. pylori eradication history and 93.4% for the model with eradication history.ConclusionsThe Kyoto classification of gastritis is useful for diagnosing H. pylori infection status based on endoscopic findings. Our prediction model is helpful for novice endoscopists. (UMIN000016674).