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Background/Aims: Lymphoepithelioma-like carcinoma (LELC) is a rare subtype of gastric cancer. We aimed to identify the clinicopathological features and rate of lymph node metastasis (LNM) to investigate the feasibility of endoscopic submucosal dissection for early gastric LELC confined to the mucosa or submucosa. Methods: We compared the clinicopathological characteristics of 116 early gastric LELC patients and 5,753 early gastric well- or moderately differentiated (WD or MD) tubular adenocarcinoma patients treated by gastrectomy. Results: Compared to WD or MD early gastric cancer (EGC) patients, early LELC patients were younger and had a higher prevalence of proximally located tumors. Despite more frequent deep submucosal invasion (86.2% vs 29.8%), lymphatic invasion was less frequent (6.0% vs 16.2%) in early LELC patients than in WD or MD EGC patients. Among tumors with deep submucosal invasion, the tumor size was smaller, lymphatic invasion was less frequent (6.0% vs 40.2%) and the rate of LNM was lower (10.0% vs 19.4%) in patients with LELC than in those with WD or MD EGC. The overall rate of LNM in early LELC patients was 8.6% (10/116). The risk of LNM in patients with mucosal, shallow submucosal invasive, or deep submucosal invasive LELC was 0% (0/6), 0% (0/10), and 10% (10/100), respectively. Conclusions: Early LELC is a distinct subtype of EGC with more frequent deep submucosal invasion but less lymphatic invasion and LNM than WD or MD EGCs. Endoscopic submucosal dissection may be considered curative for patients with early LELC confined to the mucosa or shallow submucosa, given its negligible rate of LNM.
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BACKGROUND: With the increasing resistance to antimicrobial agents, susceptibility-guided tailored therapy has been emerging as an ideal strategy for Helicobacter pylori treatment. However, susceptibility-guided tailored therapy requires additional cost, time consumption, and invasive procedure (endoscopy) and its superiority over empirical quadruple therapy as the first-line H. pylori treatment remains unclear. AIMS: To compare the efficacy of culture-based susceptibility-guided tailored versus empirical concomitant therapy as the first-line Helicobacter pylori treatment. METHODS: This open-label, randomized trial was performed in four Korean institutions. A total of 312 Patients with H. pylori-positive culture test and naïve to treatment were randomly assigned in a 3:1 ratio to either culture-based susceptibility-guided tailored therapy (clarithromycin-based or metronidazole-based triple therapy for susceptible strains or bismuth quadruple therapy for dual-resistant strains, n = 234) or empirical concomitant therapy (n = 78) for 10 days. Eradication success was evaluated by 13C-urea breath test at least 4 weeks after treatment. RESULTS: Prevalence of dual resistance to both clarithromycin and metronidazole was 8%. H. pylori eradication rates for tailored and concomitant groups were 84.2% and 83.3% by intention-to-treat analysis (p = 0.859), respectively, and 92.9% and 91.5% by per-protocol analysis, respectively (p = 0.702), which were comparable between the two groups. However, eradication rates for dual-resistant strains were significantly higher in the tailored group than in the concomitant group. All adverse events were grade 1 or 2 based on the Common Terminology Criteria for Adverse Events and the incidence was significantly lower in the tailored group. The proportion of patients discontinuing treatment for adverse events was comparable between the two groups (2.1% vs. 2.6%). CONCLUSIONS: The culture-based susceptibility-guided tailored therapy failed to show superiority over the empirical concomitant therapy in terms of eradication rate. Based on these findings, the treatment choice in clinical practice would depend on the background rate of antimicrobial resistance, availability of resources and costs associated with culture and susceptibility testing.