Eradication therapy is effective for Helicobacter pylori-negative gastric mucosa-associated lymphoid tissue lymphoma.

Mucosa-associated lymphoid tissue (MALT) lymphomas are extra-nodal B-cell lymphomas arising from MALT, and the most commonly affected organ is the stomach. Helicobacter pylori (H. pylori) eradication therapy with proton-pump inhibitors and antibiotics is the first-line therapy for H. pylori-positive gastric MALT lymphomas, but the effectiveness of the therapy for H. pylori-negative gastric MALT lymphomas remains controversial. Hence, we aimed to evaluate the effectiveness of this eradication therapy for H. pylori-negative MALT lymphomas. The H. pylori infection status of 158 gastric MALT lymphoma patients followed in our unit was judged by urea breath test, rapid urease test, histology of the biopsy specimen taken from the stomach during endoscopy, and serum antibody against H. pylori. Seventeen patients that were negative for all four tests and did not have gastric mucosal atrophy were treated with antibiotic eradication therapy. The average age at diagnosis was 56.8 years old (range: 36-73 years), and the median follow-up period after H. pylori eradication in all 17 patients was 5.3 years (range: 0.3-12.7 years). Five patients (29.4%) achieved complete remission (CR) by eradication therapy alone. Comparison between the responding and non-responding patients revealed that the patients endoscopically diagnosed to have a single lesion of gastric MALT lymphoma were seen only in the responding group, whereas all non-responding patients had multiple lesions (P < 0.05). In conclusion, H. pylori eradication therapy achieved a favorable CR rate in H. pylori-negative gastric MALT lymphoma patients and could be considered as a first-line therapy, especially for patients with a single lesion.

Signet Ring Cell Gastric Cancer Occurring after Radiation Therapy for Helicobacter pylori-Uninfected Mucosa-Associated Lymphoid Tissue Lymphoma.

Helicobacter pylori infection is the major cause for mucosa-associated lymphoid tissue (MALT) lymphoma and gastric cancers. On the other hand, gastric cancers are known to arise from gastric mucosal atrophy. We here report a case of signet ring cell gastric cancer that developed after radiation therapy for MALT lymphoma in H. pylori-uninfected patient whose stomach did not show gastric mucosal atrophy. A 58-year-old female was referred to our hospital for treatment of gastric MALT lymphoma. This patient was not infected with H. pylori, and upper gastrointestinal endoscopy revealed that she did not have gastric mucosal atrophy but had submucosal tumor-like MALT lymphoma lesion in the anterior wall of the upper gastric body. Since conventional eradication therapy was ineffective, her whole stomach was irradiated as a second-line therapy. The MALT lymphoma lesion turned into complete remission state after the therapy. The patient was followed every 6 months by upper gastrointestinal endoscopy for 4 years as complete remission until a newly developed decolorized depressed lesion was detected in the greater curvature of the proximal antrum, a completely different location from the MALT lymphoma lesion. A biopsy specimen from the lesion contained signet ring cell carcinoma, and she was successfully treated by endoscopic submucosal dissection. No signs of recurrence have been detected so far. The radiation therapy for MALT lymphoma might be associated with the occurrence of this signet ring cell gastric cancer, and since MALT lymphoma is indolent in nature, this case suggests that careful consideration is required when choosing the second-line therapy for MALT lymphoma patients.

Magnifying endoscopic findings of the surface structure of non-cancerous mucosa surrounding differentiated and undifferentiated gastric carcinoma.

BACKGROUND: Several reports have described the usefulness of magnifying endoscopy in observing the surface structure in gastric neoplasia. The aim of the present study was to evaluate the characteristics of the surface structure of non-cancerous mucosa surrounding gastric cancer. METHODS: Sixty Japanese patients with early gastric cancer were enrolled in this study. We observed the non-cancerous gastric mucosa surrounding gastric carcinoma by magnifying endoscopy and classified the magnified view into four patterns: (A) dotted; (B) short-linear; (C) striped; and (D) granular, according to Sakaki's classification. RESULTS: All patients were diagnosed as having Helicobacter pylori infection, and histological evaluation revealed 46 types of differentiated and 14 types of undifferentiated-type gastric carcinomas. There were significant differences in the gender, age and endoscopic-atrophic-border scale between patients with these two types. In all, the surface structure at 240 points (4 points each in 60 patients) of non-cancerous mucosa was observed by magnifying endoscopy. The prevalences of the surface patterns of the mucosa surrounding differentiated carcinoma were: A, 1.1%; B, 8.1%; C, 28.3%; D, 62.5%, and those of the mucosa surrounding undifferentiated carcinoma were: A, 8.9%; B, 73.2%; C, 14.3%; D, 3.6%. There were significant differences in the surface structure of the non-cancerous mucosa surrounding differentiated and undifferentiated gastric carcinoma. CONCLUSION: The microsurface structure of the gastric mucosa surrounding gastric cancer lesions differed between patients with differentiated and undifferentiated gastric cancer. These findings are expected to be useful for the early detection of gastric carcinoma lesions or for the determination of extensions of carcinoma lesions.

Topographic differences in gastric micromucosal patterns observed by magnifying endoscopy with narrow band imaging.

BACKGROUND AND AIM: The distributions and grades of Helicobacter pylori induced gastritis are known to vary among H. pylori-associated diseases. The aim of this study was to investigate the differences in distributions of gastric micromucosal structures observed by magnifying narrow band imaging (NBI) endoscopy among patients with different H. pylori-associated diseases. METHODS: Ninety-five patients with active duodenal ulcers (n = 24) and diffuse-type (n = 24) and intestinal-type (n = 47) early gastric cancers were enrolled. The magnified NBI findings were evaluated at the lesser and greater curvatures in the upper gastric corpus and were classified according to the modified A-B classification system. Biopsy specimens were also evaluated. RESULTS: In a total of 190 areas observed with magnifying NBI, histological grading (inflammation, activity, atrophy and intestinal metaplasia) showed significant differences among the classified micromucosal patterns (P < 0.001). Types B-1 and B-2, with mild atrophic changes and few areas of intestinal metaplasia, were seen mostly in the duodenal ulcers group. Types B-3 and A-1, with moderate atrophic changes, were seen in the diffuse-type early gastric cancers at the lesser curvature. Types A-1 and A-2, with severe atrophic change and a high frequency of intestinal metaplasia, were seen in the intestinal-type early gastric cancers at the lesser curvature. The prevalence of micromucosal structures differed significantly among the three groups both at the lesser and greater curvatures (P < 0.001). CONCLUSIONS: Magnifying NBI endoscopy clearly revealed detailed micromorphological differences corresponding to the histology and endoscopic findings among patients with different H. pylori-associated diseases.

Lack of modulation of gastric emptying by dietary nitrate in healthy volunteers.

Nitric oxide produced endogenously in vagal neurons modulates gastrointestinal motor activity as an important non-adrenergic and non-cholinergic neurotransmitter. Other than through endogenous biosynthesis, a high concentration of nitric oxide also occurs by chemical reactions within the stomach in the presence of gastric acid through the entero-salivary re-circulation of dietary nitrate. Although dietary nitrate can be a potential source of nitric oxide in the human stomach, there has been no report on the effect of dietary nitrate on gastric motor function. The aim of this study is to investigate the effect of dietary nitrate on gastric emptying, one of the major parameters for the gastric motor function. Fifteen healthy volunteers underwent a placebo-controlled (310 mg sodium nitrate or placebo), double-blind, crossover trial. Since a sufficient amount of gastric acid is essential for dietary nitrate-derived nitric oxide generation in the stomach, the same protocol was repeated after 1-week treatment with a proton pump inhibitor, rabeprazole. Gastric emptying was evaluated by (13)C-octanoate breath test. The sodium nitrate ingestion did not affect gastric emptying either prior to or during rabeprazole treatment, although rabeprazole treatment itself significantly delayed gastric emptying, being independent of the dietary nitrate load. Confirmation of the delayed gastric emptying with rabeprazole indicates the sensitivity of the breath test employed in the present study. In conclusion, despite the potential nitrogen source of exogenous nitric oxide, the ingestion of 310 mg sodium nitrate, which is equivalent to the average daily intake of Japanese adults, does not affect gastric emptying in healthy volunteers.

Long-term outcomes of gastric mucosa-associated lymphoid tissue lymphomas after Helicobacter pylori eradication therapy.

Mucosa-associated lymphoid tissue (MALT) lymphomas are localized primarily in the gastrointestinal tract and are characterized by an indolent nature and favorable outcome with specific therapy. Gastric MALT lymphomas are closely linked to Helicobacter pylori (H. pylori) infection, for which eradication therapy is recognized as an effective primary treatment for the disease. However, there is little information about long-term outcomes after the therapy. In the present study, we elucidated the long-term outcomes of 74 patients (70 H. pylori-positive and 4 negative cases) followed up by endoscopy at least 12 months after exclusive eradication therapy alone. The median follow-up period was 46 months. When the remission status was estimated at the time point of 12 months post-eradication, the numbers of patients with complete remission (CR), histologically residual disease with macroscopic normalization (hRD), partial remission with more than 50% tumor reduction (PR) or no response (NR) were 56, 12, 2 and 4, respectively. During follow-ups of over 12 months post-eradication, 11 of the 12 hRD cases were belatedly induced to CR but one CR case histologically relapsed into hRD. One of the 2 PR cases eventually turned into hRD 20 months later. Therefore, 66 CR, 3 hRD, 1 PR, and 4 NR cases (including 3 H. pylori-negative) were identified at the last follow-up of the present study. All 74 patients were followed up without any second-line therapies, but none exhibited disease progression. Thus, the long-term outcome of localized gastric MALT lymphoma after H. pylori eradication therapy was favorable. A watch and wait strategy may be a reasonable approach for hRD since the majority might be in the process of turning into delayed CR.