Eradication therapy is effective for Helicobacter pylori-negative gastric mucosa-associated lymphoid tissue lymphoma.

Mucosa-associated lymphoid tissue (MALT) lymphomas are extra-nodal B-cell lymphomas arising from MALT, and the most commonly affected organ is the stomach. Helicobacter pylori (H. pylori) eradication therapy with proton-pump inhibitors and antibiotics is the first-line therapy for H. pylori-positive gastric MALT lymphomas, but the effectiveness of the therapy for H. pylori-negative gastric MALT lymphomas remains controversial. Hence, we aimed to evaluate the effectiveness of this eradication therapy for H. pylori-negative MALT lymphomas. The H. pylori infection status of 158 gastric MALT lymphoma patients followed in our unit was judged by urea breath test, rapid urease test, histology of the biopsy specimen taken from the stomach during endoscopy, and serum antibody against H. pylori. Seventeen patients that were negative for all four tests and did not have gastric mucosal atrophy were treated with antibiotic eradication therapy. The average age at diagnosis was 56.8 years old (range: 36-73 years), and the median follow-up period after H. pylori eradication in all 17 patients was 5.3 years (range: 0.3-12.7 years). Five patients (29.4%) achieved complete remission (CR) by eradication therapy alone. Comparison between the responding and non-responding patients revealed that the patients endoscopically diagnosed to have a single lesion of gastric MALT lymphoma were seen only in the responding group, whereas all non-responding patients had multiple lesions (P < 0.05). In conclusion, H. pylori eradication therapy achieved a favorable CR rate in H. pylori-negative gastric MALT lymphoma patients and could be considered as a first-line therapy, especially for patients with a single lesion.