1081P - Efficacy of salvage therapy in the treatment of Helicobacter pylori-positive gastric low-grade mucosa-associated lymphoid tissue lymphoma

Abstract

BackgroundHelicobacter pylori (H.pylori) infection has a critical role in the pathogenesis of gastric mucosa-associated lymphoid tissue (MALT) lymphoma and its eradication can lead to tumor regression. However, in patients who do not achieve a lymphoma regression or relapse following antibiotic therapy, outcome of the patients are scarce. We evaluated the long-term outcome of the patients who received salvage therapy with relapsed or refractory gastric MALT lymphoma. MethodsBetween June 2000 and June 2017, a total of 29H.pylori-positive gastric MALT lymphoma patients who received frontline H.pylori eradication were included in this study. H.pylori-positive status was defined by positive results for the biopsy urease test and histology. They had all been diagnosed by endoscopy and had a complete staging including CT-scan. Patients received standard triple therapy for eradication of H.pylori and after treatment were sequentially followed-up with endoscopies performed to evaluate the response. Tumors that had resolved to complete remission (CR) score of GELA histologic grading system were considered treatment-responsive. ResultsDuring the follow-up periods 16 patients were refractory, nine had probable minimal residual disease and four relapsed after the first-line antibiotics. Of these 29 patients, transformation into high-grade B-cell lymphoma did not occur. Among the non-responder and relapsed patients, three patients were subjected to a watch and wait, while 26 patients underwent second-line treatment including radiotherapy (n=20), chemotherapy (n=5), chemotherapy plus sequential radiotherapy (n=1). Of the 20 patients treated with radiotherapy, the median dose to stomach was 3060 cGy (range, 1620-5000 cGy). After radiotherapy a CR was achieved in 20 patients (100%). Among six patients who received chemotherapy, a CR was achieved in five patients and no change was in one. That patient was achieved CR after radiotherapy. Probabilities of freedom from treatment failure and overall survival after 10 years were 100% and 83%. ConclusionsOutcome of patients with first-line H.pylori eradication failure followed by delayed chemotherapy and/or radiotherapy on indication was excellent. Legal entity responsible for the studyThe authors. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.