Management of gastric mucosa-associated lymphoid tissue lymphoma in patients with extra copies of the MALT1 gene

Extranodal marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT) type represent 7-8% of all B cell lymphomas and up to 50% of primary gastric lymphomas and can arise at any extranodal site. The most common manifestation is the stomach, which is almost invariably associated with a chronic Helicobacter pylori infection. The diagnosis is based on the histopathological evaluation of multiple gastric biopsies in accordance with the current WHO classification. The mainstay of therapy is H. pylori eradication, which must be delivered to all gastric MALT lymphoma patients, independent of stage. In patients who do not achieve lymphoma regression following antibiotic therapy, irradiation and/or systemic oncological therapies should be applied, depending on the stage of the disease. Radiotherapy might be the preferred option for localized stage. However, in the presence of disseminated or advanced disease, chemotherapy and/or immunotherapy with the anti-CD 20 antibody rituximab is the treatment of choice, but no standard chemotherapy has been defined so far. Gastric MALT lymphomas have a limited tendency to distant spreading and to histological transformation and thus MALT lymphoma usually has a favorable outcome, with an overall survival rate at 5 years of more than 85%.