A critical review of the effect of Helicobacter pylori eradication on gastric MALT lymphoma.

Low-grade B-cell lymphomas of mucosa-associated lymphoid tissue (MALT) are thought to arise within organized lymphoid tissue in the gastric mucosa that is most frequently acquired in response to Helicobacter pylori infection. This close association between the organism and the lymphoma is further reflected by the demonstration that the proliferation of the lymphoma cells can be driven by the presence of H. pylori organisms through a complex path of cellular interactions involving specific T cells. From these observations it was suggested that removal of one of the proliferative drives to the neoplastic cells in the form of eradication of the organism might induce a remission in the tumor. Several large multicenter studies are now underway to consider this question, and interim reports suggest that long-term remissions can be induced in low-grade MALT lymphomas in 70% to 80% of cases. The lymphomas that are most likely to respond to H. pylori eradication are those that are located superficially within the gastric mucosa. It has been suggested that certain genetic abnormalities, such as t(11;18) and the Bcl-10 mutation, may be associated with lack of response to this therapy. Recurrences of low-grade lymphoma are encountered in patients treated by H. pylori eradication, but these appear to be infrequent and may be self-limiting and spontaneously regress without further therapy.