LISBON, Portugal--Recent evidence linking low-grade gastric lymphoma with chronic Helicobacter pylori infection, which is said to trigger antigenic stimulation and lymphoid cell invasion of the stomach mucosa, has raised the provocative question of whether eradication of H. pylori infection can cure gastric lymphoma.
Now Swiss and Italian investigators have confirmed anecdotal reports that antibiotic treatment for H. pylori infection can accomplish regression or disappearance of low-grade gastric lymphomas without gastrectomy in as many as two thirds of patients with so-called MALT (mucosa-associated lymphoid tissue) lymphomas.
Dr. Emanuele Zucca, of San Giovanni Hospital, Bellinzona (Switzerland), said that, typically, a 2-week regimen of amoxicillin(Drug information on amoxicillin), 500 mg tid, metronidazole(Drug information on metronidazole), 400 mg tid, and bismuth, 120 mg qid, with or without omeprazole(Drug information on omeprazole), was prescribed for the 25 patients with stage IE gastric MALT lymphoma who comprised the study population.
Antimicrobial therapy successfully eradicated infection in 96% of patients and completely relieved symptoms of abdominal pain and dyspepsia in 77%, Dr. Zucca reported at the congress of the European Society of Medical Oncology. Most important, he stressed, bimonthly gastroscopic examinations revealed lymphoma regression in 15 (60%) of 25 patients, with one patient demonstrating wholly normal histology and the remaining 14 showing only histologic features of chronic gastritis.
"Lymphoma regression may take quite a long time," Dr. Zucca cautioned. He pointed out that regression was documented within 6 months of antibiotic therapy in eight of the 15 responding patients but not until 9 to 12 months following treatment in the seven other responders.
"Before concluding that antibiotic treatment can cure gastric lymphoma, prolonged careful follow-up will be necessary because of the long natural history of this disease," Dr. Zucca said. "At present, however, an attempt to eradicate this infection is mandatory before considering any other therapeutic options in low-grade gastric lymphoma."
A randomized trial involving centers in Switzerland, Italy, and Britain is being launched to investigate whether following antibiotic treatment with chemotherapy provides any additional benefit.