Clinical Research Directory

Inclusion Criteria: 1. The patients must have histologically confirmed primary gastric MALT lymphoma by REAL/WHO classification 2. The patient must have no prior chemotherapy or radiotherapy for his/her gastric MALT lymphoma 3. Patients must have evaluable disease by endoscopy and/or the nodal status by computed tomography 3.1 If patients have endoscopic lesions without computed tomography-demonstrating lesions are eligible. 3.2 Endoscopic ultrasonography (EUS) is optional to evaluate the depth of tumor infiltration and for status of perigastric lymph node enlargement 4. Patients must have documented to have no HP infection before treatment, which will be evaluated by the following tests: histology, rapid urease test (CLO-test), C-13 urease breath test, HP stool antigen, and serology; and all of the five tests have to be negative for the diagnosis of no evidence of HP infection. 5. Patients must have either stage IE or IIE1 disease, according to an adaptation of the Ann Arbor staging system modified by Musshoff for primary extranodal lymphoma. 6. Patients must have signed the informed consent and agree to provide achieved pathologic material and tumor biopsy for translational study 7. Patients must have signed the informed consent and agree to provide achieved blood samples for potential serum molecular studies and fecal samples for researches of gut microbiota Exclusion Criteria: 1. Active second malignancies during the last five years except non melanomatous skin cancer, carcinoma in situ of cervix, lobular or ductal carcinoma in situ of breast. 2. Patients with previous history of extranodal lymphoma are not eligible. 3. Patients with stage IIE2 or beyond disease: infiltration of regional lymph nodes not adjacent primary involved site. 4. Patients with cardiopulmonary status that do not allow repeat examination are not eligible. 5. Patients with prior chemo- or radiotherapy for their extragastric lymphoma are not eligible.