Background & aims: Recent studies suggest that eradication of Helicobacter pylori may result in complete regression of low-grade lymphoma of the gastric mucosa-associated lymphoid tissue (MALT). Which patients benefit from this treatment is unknown. The aim of this study was to prospectively study whether staging by echoendoscopy predicts the outcome of treatment of MALT lymphoma by eradication of H. pylori.
Methods: Twenty-two patients positive for H. pylori with low-grade gastric B-cell MALT lymphoma were examined by echoendoscopy at the time of diagnosis. Treatment for H. pylori consisted of a 2-week course of oral omeprazole and amoxicillin. Patients were followed up by endoscopy and biopsy.
Results: H. pylori was eradicated in all patients. Complete regression of MALT lymphoma was observed in 12 patients (54%), partial regression in 5 patients (23%), and no response in 5 patients (23%) during follow-up. Twelve of 14 patients with lymphoma restricted to the mucosa or submucosa (stage E-I1) at echoendoscopy, but none of the 10 patients with higher stage (P < 0.01), showed complete regression of MALT lymphoma. In stage E-I1 patients, the probability of complete regression of lymphoma was 60% at 6, 79% at 12, and reached 100% at 14 months, respectively.
Conclusions: Staging of gastric low-grade MALT lymphomas by endoscopic ultrasonography allows prediction of the response to therapy by eradication of H. pylori.