Long-term efficacy and toxicity of rituximab plus fludarabine and mitoxantrone (R-FM) for gastric marginal zone lymphoma: a single-center experience and literature review

Long-term clinical outcomes of gastric mucosa-associated lymphoid tissue lymphoma in real-world experience

This long-term, retrospective, single-center study evaluated real-world clinical outcomes of gastric mucosa-associated lymphoid tissue (MALT) lymphoma using different therapeutic modalities and analyzed factors affecting survival outcomes and long-term prognosis. We enrolled 203 patients with pathologically confirmed low-grade gastric MALT lymphoma and examined their treatment responses. Helicobacter pylori eradication was performed in all patients with H. pylori infection (HPI) and localized stage gastric MALT lymphoma. All patients underwent pre-treatment and physical evaluations, with complete blood count, biochemistry panel, and staging workup. Among 144 HPI-positive patients with stage I or II1-2 disease who underwent H. pylori eradication, 112 (77.8%) achieved complete remission (CR). All HPI-negative patients who received first-line radiotherapy achieved CR (100%), but only 22 of 27 first-line chemotherapy-treated patients achieved CR (81.5%). Lesions in the proximal upper-third or in multiple locations and an invasion depth to the submucosa or deeper were associated with poor response to eradication, and HPI negativity was significantly correlated with poor progression-free survival. HPI eradication treatment should be the first-line treatment for patients with localized stage HPI-positive gastric MALT lymphoma. The "watch-and-wait" strategy should be adopted for delayed responders. We suggest radiotherapy for patients with a localized HPI-negative status or when eradication has failed.

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.

Management of Extranodal Marginal Zone Lymphoma: Present and Upcoming Perspectives

Simple Summary

Extranodal marginal zone lymphoma distinguishes itself from other indolent lymphomas due to its unique pathophysiology and natural history. This is reflected in its management, where next to traditional treatment strategies such as observation, radiotherapy or chemotherapy, eradication of the causal agent and even surgery represent important aspects of therapy. This review focuses on the particular aspects of this indolent lymphoma that affect management and summarizes the current evidence and different guidelines.

Abstract

Extranodal marginal zone lymphoma (EMZL) encompasses a subgroup of non-Hodgkin lymphomas that often present with localized involvement and may manifest in a diversity of organs and tissues. EMZL pathogenesis is in some cases linked to chronic inflammation/infection, which may impose additional diagnostic and clinical challenges. The most studied and established connection is the presence of Helicobacter pylori in gastric EMZL. Due to its heterogeneity of presentation and intricate pathological features, treatment can be complex, and staging systems are decisive for the choice of therapy. Nevertheless, there is no consensus regarding the most suitable staging system, and recommendations vary among different countries. As a rule of thumb, in limited stages, a local therapy with surgery or radiation is the preferred option, and it is potentially curative. Of note, eradicating the causal agent may be an important step of treatment, especially in gastric EMZL, in which Helicobacter pylori eradication remains the first-line therapy for the majority of patients. In patients with more advanced stages, watch-and-wait is a valuable option, especially amongst those without clear indications for systemic therapy, and it may be carried on for several years. If watch-and-wait is not an option, systemic therapy may be needed. Even though several agents have been tested as monotherapy or in combination in recent years, there is no consensus regarding the first-line therapy, and decisions can vary depending on individual factors, such as age, clinical performance and stage. This review aims to discuss the several aspects of EMZL, including genetic milieu, pathogenesis and staging systems, that may influence the choice of therapy. In addition, we present a summary of evidence of several systemic therapies, compare different recommendations worldwide and discuss future perspectives and novelties in its therapy.

Current Status of the Spectrum and Therapeutics of Helicobacter pylori-Negative Mucosa-Associated Lymphoid Tissue Lymphoma

Helicobacter pylori (HP)-unrelated mucosa-associated lymphoid tissue (MALT) lymphoma includes the majority of extragastric MALT lymphomas and a small proportion of gastric MALT lymphomas. Although the role of first-line antibiotics in treating HP-negative gastric MALT lymphomas remains controversial, HP eradication therapy (HPE)-like regimens may result in approximately 20-30% complete remission (CR) for patients with localized HP-negative gastric MALT lymphoma. In these patients, H. heilmannii, H. bizzozeronii, and H. suis were detected in sporadic gastric biopsy specimens. Extragastric MALT lymphoma is conventionally treated with radiotherapy for localized disease and systemic chemotherapy for advanced and metastatic diseases. However, a proportion of extragastric MALT lymphomas, such as ocular adnexal lesions and small intestinal lesions, were reported to be controlled by antibiotics for Chlamydophila psittaci and Campylobacter jejuni, respectively. Some extragastric MALT lymphomas may even respond to first-line HPE. These findings suggest that some antibiotic-responsive tumors may exist in the family of HP-negative MALT lymphomas. Two mechanisms underlying the antibiotic responsiveness of HP-negative MALT lymphoma have been proposed. First, an HPE-like regimen may eradicate the antigens of unknown bacteria. Second, clarithromycin (the main component of HPE) may have direct or indirect antineoplastic effects, thus contributing to the CR of these tumors. For antibiotic-unresponsive HP-negative MALT lymphoma, high-dose macrolides and immunomodulatory drugs, such as thalidomide and lenalidomide, have reported sporadic success. Further investigation of new treatment regimens is warranted.