[Prognostic impact of Helicobacter pylori infection and eradication therapy in gastric mucosa-associated lymphoid tissue lymphoma].

BACKGROUND Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is associated with Helicobacter pylori infection and H. pylori eradication is used as its first-line therapy. However, controversies exist about the prognostic value of H. pylori infection in these patients. We evaluated the prognostic impact of H. pylori infection and eradication therapy in gastric MALT lymphoma. METHODS A total of 292 patients diagnosed with MALT lymphoma since 2000 were analysed. MALT lymphoma was diagnosed with tissue biopsy and H. pylori infection was diagnosed with hematoxylin-eosin and additional Warthin-Starry stains on tissue sections. Clinical variables such as bone marrow (BM) involvement, multiorgan involvement, tumor stage at diagnosis, and remission were obtained with retrospective review of electronic medical records. RESULTS Non-gastric MALT lymphoma patients showed higher multiorgan involvement rates (26.6% vs. 9.6%, P<0.001) and higher proportion of stage ≥ 3 (27.7% vs. 16.7%, P=0.029) than gastric cases. Regarding gastric MALT lymphoma, patients with H. pylori infection at diagnosis showed significantly less BM (2.1% vs. 21.8%, P<0.001) and multiorgan involvement rates (6.3% vs. 18.2%, P=0.011) than those without infection. But there was no significant difference in remission rates between them. In contrast, those with successful H. pylori eradication therapy showed significantly higher remission rates (81.0% vs. 30.8%, P<0.001) than those with failure. CONCLUSIONS Non-gastric MALT lymphoma patients showed worse prognosis compared to gastric cases. As for remission rates in patients with gastric MALT lymphoma, successful H. pylori eradication therapy could be a good prognostic factor even if H. pylori infection was present at diagnosis.