Introduction The eradication rates for Helicobacter pylori have decreased in Korea although the prevalence of this bacterium has also decreased. Antibiotic resistance is likely to be a crucial factor in H. pylori eradication success, and we therefore mapped these resistance patterns nationwide in Korea. Materials and Methods Five hundred and ninety adult subjects were prospectively enrolled from 2017 to 2018 from 15 centers across six geographic areas of Korea. A total of 580 biopsy tissues had been sampled from these patients during an upper endoscopy and were frozen at −80°C and delivered to a central laboratory. The agar dilution method was used to determine the minimum inhibitory concentration of amoxicillin, clarithromycin, metronidazole, tetracycline, ciprofloxacin, and levofloxacin for each H. pylori isolate. Results The culture success rate was 60.2% (349/580). Resistance rates against clarithromycin, metronidazole, amoxicillin, tetracycline, levofloxacin, and ciprofloxacin were 17.8%, 29.5%, 9.5%, 0%, 37.0%, and 37.0%, respectively. The geographic distribution of metronidazole and quinolone resistance was highly variable. Some subjects had multiple H. pylori strains in the antrum and body of the stomach and showed a heterogeneous resistance profile between these anatomic areas. The H. pylori multidrug resistance (MDR) rate was 25.2% (88/349) among amoxicillin, clarithromycin, metronidazole, tetracycline, and quinolone and 11.2% (39/349) among four of these major antibiotics except for quinolone. The Seoul and Chungcheong areas showed a relatively lower MDR rate. Conclusion The antibiotic resistance of H. pylori differs by drug and geographic area in Korea. Detailed nationwide antibiotic resistance mapping is needed to develop an effective H. pylori eradication strategy.

The endoscopic clip closure procedure can significantly reduce the frequency of surgery among patients with iatrogenic colon perforations. However, the decision for surgery must be made early after endoscopic clip closure to prevent adverse complications for patients with higher risk factors.

BACKGROUND & AIMS: Besifovir dipivoxil maleate (BSV) has activity against hepatitis B virus (HBV). We performed a phase 3 study to compare the antiviral efficacy and safety of BSV vs tenofovir disoproxil fumarate (TDF) in patients with chronic HBV infection in Korea. METHODS: We conducted a double-blind, non-inferiority trial of 197 patients with chronic HBV infection at 22 sites in South Korea, from November 2013 through February 2016. Patients were randomly assigned to groups given BSV (150 mg, n [ 99) or TDF (300 mg, n [ 98) for 48 weeks. We evaluated virologic responses to therapy (HBV DNA <69 IU/mL or 400 copies/ml), bone mineral density (BMD), and renal outcomes for safety analysis. The main efficacy endpoint was the proportion of patients with a virologic response at week 48. After 48 weeks, TDF was switched to BSV (150 mg) for an additional 48 weeks. RESULTS: After 48 weeks of treatment, 80.9% of patients given BSV and 84.9% of patients given TDF met the efficacy endpoint, indicating the non-inferiority of BSV to TDF. At week 96, 87.2% of a Authors share co-first authorship.

One of the most important prognostic factors in esophageal carcinoma is lymph node metastasis, and in particular, the number of affected lymph nodes, which influences long-term outcomes. The esophageal lymphatic system is connected longitudinally and transversally; thus, the pattern of lymph node metastases is very complex. Early esophageal cancer frequently exhibits skipped metastasis, and minimal surgery using sentinel node navigation cannot be performed. In Korea, most esophageal cancer cases are squamous cell carcinoma (SCC), although the incidence of adenocarcinoma has started to increase recently. Most previous reports have failed to differentiate between SCC and adenocarcinoma, despite the fact that the Union for International Cancer Control (7th edition) and American Joint Committee on Cancer staging systems both consider these separately because they differ in cause, biology, lymph node metastasis, and outcome. Endoscopic tumor resection is an effective and safe treatment for lesions with no associated lymph node metastasis. Esophageal mucosal cancer confined to the lamina propria is an absolute indication for endoscopic resection, and a lesion that has invaded the muscularis mucosae can be cured by local resection if invasion to the lymphatic system has not occurred.