Clinical efficacy of the modified Helicobacter pylori eradication therapy for Helicobacter pylori-negative gastric mucosa-associated lymphoid tissue lymphoma: a meta analysis

Clinical features and temporal trends in H. pylori negative gastric maltoma

BACKGROUND

Mucosa-Associated Lymphoid Tissue (MALT) lymphoma or MALToma is a type of non-Hodgkin lymphoma arising in the gastric mucosa that has largely been associated with Helicobacter pylori (H. pylori) infection. However, less than 10% of gastric MALTomas can occur with a negative H. pylori status, and the disease seems to have a different course.

PATIENTS AND METHODS

Patients diagnosed with MALToma from 2000 to 2021 were included in the study. H. pylori-negative (HPN) status was confirmed when patients had at least 2 negative tests among the following: urea breath test, rapid urease test, serological test, or histology. The patients were divided into H. pylori positive (HPP) and HPN groups.

RESULTS

The final analysis included 52 gastric MALToma patients, 25 (48.1 %) were HPN. Demographics and disease stages were comparable between the two groups, although a higher prevalence of HPN cases emerged in patients diagnosed from 2011 to 2021 compared to the 2000-2010 period (55.3 % vs. 28.6 %, p = 0.09). All patients in the HPP group received eradication therapy (ET) compared to only 40 % in the HPN group. ET success in the stage 1 HPN group was 25 % compared to 78.6 % in the HPP group (p = 0.03). More patients in the HPN group received chemo and/or radiotherapy compared to the HPP (86.4 % vs 57.1 %, p = 0.033). Treatment outcomes were similar between both groups. Comparing stage 1 MALToma patients who responded to ET versus non-responders revealed that responders were more likely to be HPP (76.8 % vs. 33.3 %, p = 0.026) and diagnosed in the earlier period (2000-2010, p = 0.048).

CONCLUSION

HPN MALToma patients were similar to HPP patients in clinical features. However, there was an increase in diagnosis of HPN MALToma and a decrease in response to ET in more recent years.

Role of non-Helicobacter pylori gastric Helicobacters in helicobacter pylori-negative gastric mucosa-associated lymphoid tissue lymphoma

Marginal zone lymphomas rank as the third most prevalent form of non-Hodgkin B-cell lymphoma, trailing behind diffuse large B-cell lymphoma and follicular lymphoma. Gastric mucosa-associated lymphoid tissue lymphoma (GML) is a low-grade B-cell neoplasia frequently correlated with Helicobacter pylori (H. pylori)-induced chronic gastritis. On the other hand, a specific subset of individuals diagnosed with GML does not exhibit H. pylori infection. In contrast to its H. pylori-positive counterpart, it was previously believed that H. pylori-negative GML was less likely to respond to antimicrobial therapy. Despite this, surprisingly, in-creasing evidence supports that a considerable proportion of patients with H. pylori-negative GML show complete histopathological remission after bacterial eradication therapy. Nonetheless, the precise mechanisms underlying this treatment responsiveness are not yet fully comprehended. In recent years, there has been growing interest in investigating the role of non-H. pylori gastric helicobacters (NHPHs) in the pathogenesis of H. pylori-negative GML. However, additional research is required to establish the causal relationship between NHPHs and GML. In this minireview, we examined the current understanding and proposed prospects on the involvement of NHPHs in H. pylori-negative GML, as well as their potential response to bacterial eradication therapy.

Clinical Management of Patients with Gastric MALT Lymphoma: A Gastroenterologist's Point of View

Gastric mucosa-associated lymphoid tissue (MALT) lymphomas (GML) are non-Hodgkin lymphomas arising from the marginal zone of the lymphoid tissue of the stomach. They are usually induced by chronic infection with Helicobacter pylori (H. pylori); however, H. pylori-negative GML is of increasing incidence. The diagnosis of GML is based on histological examination of gastric biopsies, but the role of upper endoscopy is crucial since it is the first step in the diagnostic process and, with currently available novel endoscopic techniques, may even allow an in vivo diagnosis of GML per se. The treatment of GML, which is usually localized, always includes the eradication of H. pylori, which should be performed even in H. pylori-negative GML. In the case of GML persistence after eradication of the bacteria, low-dose radiotherapy may be proposed, while systemic treatments (immunochemotherapy) should be reserved for very rare disseminated cases. In GML patients, at diagnosis but even after complete remission, special attention must be paid to an increased risk of gastric adenocarcinoma, especially in the presence of associated gastric precancerous lesions (gastric atrophy and gastric intestinal metaplasia), which requires adequate endoscopic surveillance of these patients.

Management of Marginal Zone Lymphoma: A Canadian Perspective

Marginal zone lymphomas (MZL) are a rare, heterogenous group of lymphomas, accounting for 5-17% of indolent non-Hodgkin lymphomas in the western world. They can be further divided into three subtypes: extranodal MZL, splenic MZL, and nodal MZL. These subtypes differ in clinical presentation and behavior, which influences how they are managed. There is currently no standard of care for the treatment of MZL, owing to the difficulty in conducting phase 3 randomized trials in MZL, and the fact that there are limited data on the efficacy of therapy in individual subtypes. Treatment practices are thus largely borrowed from other indolent lymphomas and are based on patient and disease characteristics, as well as access to therapy. This review summarizes the Canadian treatment landscape for MZL and how these therapies may be sequenced in practice.

Diagnosis and Treatment for Gastric Mucosa-Associated Lymphoid Tissue (MALT) Lymphoma

Mucosa-associated lymphoid tissue (MALT) lymphoma, which was first reported in 1984, shows an indolent clinical course. However, the detailed clinicopathological characteristics of gastric MALT lymphoma have not been fully elucidated. We performed a literature search concerning the clinical features and treatment for gastric MALT lymphoma using PubMED. MALT lymphomas develop in single or multiple extranodal organs, of which the stomach is one of the most frequent sites; gastric MALT lymphoma accounts for 7% to 9% of all B-cell lymphomas, and 40% to 50% of primary gastric lymphomas. The eradication of Helicobacter pylori (H. pylori) is the first-line treatment for patients with gastric MALT lymphoma, regardless of the clinical stage. Approximately 60-90% of cases with stage I/II₁ disease only achieve a complete histological response via H. pylori eradication. In patients who do not respond to H. pylori eradication therapy, second-line treatments such as watch-and-wait, radiotherapy, chemotherapy, rituximab immunotherapy, and/or a combination of these are recommended. Thus, H. pylori plays a causative role in the pathogenesis of gastric MALT lymphoma, and H. pylori eradication leads to complete histological remission in the majority of cases.

Helicobacter pylori-Negative Gastric Mucosa-Associated Lymphoid Tissue Lymphoma Presenting as Massive Gastrointestinal Bleed

This case reports a patient that represents the minority of patients with gastric mucosa-associated lymphoid tissue (MALT) lymphoma who do not have underlying Helicobacter pylori gastritis. Gastric MALT lymphoma is a type of primary gastric lymphoma (PGL), which are extremely rare gastric malignancies characterized by proliferation of B-cells and infiltration of lymphoid tissue leading to destruction of gastric glands. Development of gastric MALT lymphoma is associated with H. pylori gastritis. Patients typically present with a wide range of symptoms including but not limited to epigastric pain, weight loss, gastrointestinal bleeding and gastric wall perforation. Gastric MALT lymphoma presenting as a massive gastrointestinal bleed is quite rare and only a few cases have been documented. Our case demonstrates that it is important to recognize that acute presentations of this disease may also occur. 

Investigation of endoscopic findings in nine cases of Helicobacter suis-infected gastritis complicated by gastric mucosa-associated lymphoid tissue lymphoma

BACKGROUND

We have previously reported that eradication therapy was more effective against Helicobacter pylori (Hp)-negative gastric mucosa-associated lymphoid tissue (MALT) lymphoma in non-Helicobacter pylori Helicobacter (NHPH)-positive cases than in NHPH-negative cases and that the infection status of NHPH could be a predictive marker for the efficacy of eradication therapy for H. pylori negative gastric MALT lymphoma. However, a diagnostic test for NHPH infection has not yet been clinically established. In this study, we investigated the endoscopic findings in cases of H. suis-infected gastritis associated with gastric MALT lymphoma reported at our institution.

MATERIALS AND METHODS

Participants were selected from cases of gastric MALT lymphoma who underwent esophagogastroduodenoscopy at Hiroshima University Hospital, who were negative for the API2-MALT1 gene, and who received eradication therapy as a first-line treatment. We examined the endoscopic findings in nine cases from this group in which H. suis infection was confirmed by polymerase chain reaction.

RESULTS

Endoscopic findings, such as cracked mucosa, spotty redness, nodular gastritis-like appearance, and white marbled appearance, which have been reported as characteristics of NHPH gastritis, were observed in multiple cases. The most common endoscopic findings in this study were cracked mucosa (7/9 cases), followed by spotty redness (6/9 cases), nodular gastritis-like appearance (5/9 cases), and white marbled appearance (2/9 cases).

CONCLUSIONS

Our study may serve as a reference for re-evaluation of the diagnostic criteria for H. suis infection and indications for eradication therapy, particularly for cases of H. pylori negative gastric MALT lymphoma, where endoscopic findings such as those seen in this study were observed in the background mucosa.