Mo1570 Endoscopic and Histopathological Changes After Helicobacter Pylori Eradication Therapy in Patients With Gastric MALT Lymphoma

We investigated the endoscopic and histopathological changes after Helicobacter pylori (H. pylori) eradication therapy in patients with gastric MALT lymphoma. Eighty-nine patients with gastric MALT lymphoma (complete remission (CR) after H. pylori eradication therapy: 77 patients, non-CR: 12 patients) who had undergone H. pylori eradication therapy in Okayama University Hospital were enrolled in this study to evaluate the endoscopic improvement (diminished lesion), the endoscopic remission (atrophic discolored mucosa), and the time taken to achieve CR after the eradication therapy. The histological changes were assessed by Wotherspoon's grading (WG) system, and grades less than WG2 were considered as CR. In addition, the lesions were macroscopically classified into superficial type, ulcerative type, and protruded type. When endoscopic improvement was observed, the lesions were CR in 5 patients, WG3 in 8, WG4 in 11, and WG5 in 11. When endoscopic remission was observed, the lesions were CR in 67 patients, WG3 in 6, WG4 in 2, and WG5 in 2. The time taken to achieve CR after the eradication therapy were less than 3 months in 30 patients (39%), less than 6 months in 54 (77%), and less than a year in 72 (94%). The median periods taken to achieve endoscopic improvement, endoscopic remission, and CR were 58 (30-193), 138 (30-550), and 138 (30-1739) days, respectively. Considering the macroscopic type, these periods were 63, 137, and 141 days, respectively, for the superficial type (58 patients), 73, 140, and 101 days, respectively, for the ulcerative type (11 patients), and 99, 135, and 104 days, respectively, for the protruded type (8 patients). In the patients with the superficial type, endoscopic remission occurred at almost the same time with CR, whereas the endoscopic remission was delayed in the ulcerative and protruded types.On the other hand, among the 12 non-CR patients, API2-MALT1 was positive in 4 patients, negative in 6 patients, and unknown in 2 patients. The median period taken to perform second-line treatment after the eradication therapy was 211 (range: 55-508) days. Although endoscopic remission was not observed in any patients, endoscopic improvement was observed within 3 months in 2 (superficial type) of the 6 patients without API2-MALT1. The other 4 patients showed no change (2 protruded types and 2 superficial types). None of the 4 patients with API2-MALT1 showed endoscopic changes. The period taken to achieve CR after H. pylori eradication therapy in the patients with gastric MALT lymphoma varied, and the endoscopic changes were not always consistent with the histological changes. However, watchful waiting is allowed if endoscopic improvement is observed after eradication.