Eradication of Helicobacter Pylori in the Management of Stage IE & IIE-1 Primary Low-grade B Cell Lymphoma of MALToma

Inclusion Criteria: The patients must have histologically confirmed primary low-grade B-cell lymphoma of MALT of the stomach which including the following types : diffuse small lymphocytic, diffuse small cleaved, and some diffuse mixed small and large cell types by Working Formulation (Harris NL et al. 1994)(20). The diagnosis of primary gastric lymphoma must fulfill the criteria of Dawson : No enlargement of peripheral or mediastinal lymph node; Peripheral blood smear revealing no leukemic or lymphomatous abnormalities; Predominant of alimentary tract lesions with any adenopathy corresponding to accepted lymphatic drainage route; and No involvement of liver or spleen except by extension of contiguous disease . The monoclonality of B-cell must be confirmed by either immunohisto- chemistry (light-chain restriction) or molecular technique (IgH rearrangement). The patient must have no prior chemotherapy or radiotherapy for his/her gastric MALToma. Patients must have evaluable disease by endoscopy and the nodal status by computed tomography. Endoscopic ultrasonography (EUS)* is optional and for reference only. H. pylori infection will be evaluated by the following tests: histology, rapid urease test (CLO-test), and serology C13-urea breath test (UBT) and bacterial culture* are optional and for reference only. The following will be considered to have H. pylori infection : at least two of the following 3 tests show positive results, rapid urease test (CLO-test), histology and serology. For C13-urea breath test, rapid urease test and histology to examine H. pylori, the examination must be performed at least 4 weeks apart from the latest antibiotics or non-steroid anti-inflammatory drug ingestion. Patients must have either stage IE or IIE-1 disease, according to an adaptation of the Ann Abor staging system modified by Musshoff for primary extranodal lymphoma. Stage IE : lymphoma confined to the gastric wall without lymph node involvement. Stage IIE : localized involvement of one or more GI site(s) on one side of the diaphragm with lymph node infiltration, any depth of lymphoma infiltration into the gut wall. Stage IIE-1 : infiltration of adjacent lymph node. Patient must have signed the informed consent. Exclusion Criteria: Patients who have extensive gastrointestinal tract involvement are not eligible. Patients who have had previous history of extranodal lymphoma are not eligible. Patients who have disease beyond stage IIE-2: infiltration of regional lymph node, e.g. paraaortic, renal hilar, retroperitoneal, mesenteric, or lymph node of gastrosplenic ligment and of hepatoduodenal ligment are not eligible. Patients who had a history of allergic reaction to Amoxicillin and Erythromycin /Clarithromycin are not eligible. Patients whose cardiopulmonary status not allow him/her to have repeat endoscopy are not eligible. Patients who had prior surgery, chemo- or radiotherapy for their primary gastric lymphoma are not eligible. Patients who had previous anti-H. pylori therapy are not eligible.