Addition of rituximab to chlorambucil produces superior event-free survival in the treatment of patients with extranodal marginal-zone B-cell lymphoma: 5-year analysis of the IELSG-19 Randomized Study

Role of Helicobacter pylori in gastric mucosa-associated lymphoid tissue lymphomas

Mucosa-associated lymphoid tissue (MALT) lymphoma is an indolent extranodal marginal zone B-cell lymphoma, originating in acquired MALT that is induced in mucosal barriers as part of a normal adaptive immune response to a chronic immunoinflammatory stimulus, most notably chronic infection by Helicobacter pylori (H. pylori). This antigenic stimulation initially leads to lymphoid hyperplasia; the acquisition of additional genetic aberrations culminates in the activation of intracellular survival pathways, with disease progression due to proliferation and resistance to apoptosis, and the emergence of a malignant clone. There are descriptions of MALT lymphomas affecting practically every organ and system, with a marked geographic variability partially attributable to the epidemiology of the underlying risk factors; nevertheless, the digestive system (and predominantly the stomach) is the most frequently involved location, reflecting the gastrointestinal tract’s unique characteristics of contact with foreign antigens, high mucosal permeability, large extension and intrinsic lymphoid system. While early-stage gastric MALT lymphoma can frequently regress after the therapeutic reversal of the chronic immune stimulus through antibiotic eradication of H. pylori infection, the presence of immortalizing genetic abnormalities, of advanced disease or of eradication-refractoriness requires a more aggressive approach which is, presently, not consensual. The fact that MALT lymphomas are rare neoplasms, with a worldwide incidence of 1-1.5 cases per 10⁵ population, per year, limits the ease of accrual of representative series of patients for robust clinical trials that could sustain informed evidence-based therapeutic decisions to optimize the quality of patient care.

Chlorambucil-Induced Acute Interstitial Pneumonitis

Chlorambucil is an alkylating agent commonly used in treatment of chronic lymphocytic leukemia (CLL). We report a case of interstitial pneumonitis developing in an 83-year-old man 1.5 months after completing a six-month course of chlorambucil for CLL. The interstitial pneumonitis responded to therapy with prednisone. We performed a systematic review of literature and identified 13 other case reports of chlorambucil-induced pulmonary toxicity, particularly interstitial pneumonitis. No unifying risk factor could be discerned and the mechanism of injury remains unknown. In contrast, major randomized trials of chlorambucil therapy in CLL have not reported interstitial pneumonitis as an adverse effect, which may be due to the rarity of the phenomenon or due to underreporting of events occurring after completion of treatment. Clinicians should consider drug-induced interstitial pneumonitis in the differential diagnosis of a suggestive syndrome developing even after discontinuation of chlorambucil.

Bulky pulmonary mucosa-associated lymphoid tissue lymphoma treated with yttrium-90 ibritumomab tiuxetan

An 84-year-old woman was admitted to our hospital with nonproductive cough and dyspnea on exertion. Computed tomography (CT) scan revealed extensive consolidation in the right lung. She was diagnosed with pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma using CT-guided lung biopsy. Her pulmonary images and respiratory symptoms did not improve two months after receiving 4 cycles of rituximab weekly; therefore, yttrium-90 ibritumomab tiuxetan was chosen as salvage therapy. The abnormal shadow on her pulmonary images was significantly reduced two months later, and she had no symptoms without nonhematological toxicities. She has had no progression for 18 months. Furthermore, radiation pneumonitis has not also been observed. We herein reported bulky pulmonary MALT lymphoma treated with yttrium-90 ibritumomab tiuxetan.

Helicobacter pylori and gastric mucosa-associated lymphoid tissue lymphoma: Recent progress in pathogenesis and management

Recent progress in the research regarding the molecular pathogenesis and management of gastric mucosa-associated lymphoid tissue (MALT) lymphoma is reviewed. In approximately 90% of cases, Helicobacter pylori (H. pylori) infection plays the causative role in the pathogenesis, and H. pylori eradication is nowadays the first-line treatment for this disease, which leads to complete disease remission in 50%-90% of cases. In H. pylori-dependent cases, microbe-generated immune responses, including interaction between B and T cells involving CD40 and CD40L co-stimulatory molecules, are considered to induce the development of MALT lymphoma. In H. pylori-independent cases, activation of the nuclear factor-κB pathway by oncogenic products of specific chromosomal translocations such as t(11;18)/API2-MALT1, or inactivation of tumor necrosis factor alpha-induced protein 3 (A20) are considered to contribute to the lymphomagenesis. Recently, a large-scale Japanese multicenter study confirmed that the long-term clinical outcome of gastric MALT lymphoma after H. pylori eradication is excellent. Treatment modalities for patients not responding to H. pylori eradication include a “watch and wait” strategy, radiotherapy, chemotherapy, rituximab immunotherapy, and a combination of these. Because of the indolent behavior of MALT lymphoma, second-line treatment should be tailored in consideration of the clinical stage and extent of the disease in each patient.

Treatment of gastric marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue with rituximab, cyclophosphamide, vincristine and prednisone

There is no standard treatment for patients with gastric marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT lymphoma) who are resistant to, or ineligible for, anti-Helicobacter pylori (anti-HP) therapy. In this study, we investigated the activity of the rituximab, cyclophosphamide, vincristine and prednisone (R-CVP) regimen in patients with gastric MALT lymphoma. Patients were included provided they had untreated gastric MALT lymphoma (except for anti-HP therapy) and were resistant to, or ineligible for, anti-HP therapy. Treatment plan consisted of six to eight 21-day cycles of the R-CVP chemotherapy regimen. Toxicity, response, relapse and survival were evaluated. Twenty patients (12 women and 8 men) were included in the analyses with median age of 59 years. Thirteen patients (65%) had stage I tumours, and seven patients (35%) had stages II-IV tumours. The overall response rate was 100%, with 19 (95%) complete responses and one (5%) partial response. Regimen toxicity was mild and mainly hematological, and no cases of gastric bleeding or perforation occurred. After a median follow-up of 56.3 months, three patients had relapsed, and 19 patients remained alive (specific lymphoma survival 100%), of whom 17 had no evidence of disease. In our experience, the R-CVP regimen is a well-tolerated and effective treatment for patients with gastric MALT lymphoma who are resistant to, or ineligible for, anti-HP therapy.

Marginal zone lymphomas and infectious agents

A link with infectious agents, bacteria and viruses in particular, has been reported for many lymphoma entities. Marginal zone lymphomas (extranodal, nodal and splenic forms) are frequently associated with chronic infections, with important clinical, molecular, biological, and therapeutic implications. The well-known correlation between Helicobacter pylori and gastric MALT-lymphoma, the recently reported links between Chlamydophila psittaci and ocular adnexal MALT-lymphoma and Borrelia burgdorferi and cutaneous MALT lymphoma constitute the best studied examples of lymphomagenic activity of bacteria, while the hepatitis C virus represents the most extensively investigated virus associated with marginal zone lymphomas. Biological and clinical features, therapeutic implications and future perspectives of these lymphoma-microbial associations are discussed in this review.

Rituximab in the treatment of non-Hodgkin's lymphoma--a critical evaluation of randomized controlled trials

INTRODUCTION

The use of rituximab has led to significant improvements in the outcome of both aggressive and indolent Non-Hodgkin's lymphoma (NHL). It is the first targeted therapy to be developed for the treatment of lymphoma which has been widely adopted.

AREAS COVERED

This paper discusses the use of rituximab in NHL, mainly concentrating on diffuse large B cell lymphoma (DLBCL) and follicular lymphoma (FL), with a brief discussion about use in other types of NHL including mantle cell lymphoma (MCL). The use of rituximab in chronic lymphocytic leukemia (CLL) has been recently published in this journal by Robak (Robak T. Rituximab for chronic lymphocytic Leukemia. Expert Opin Biol. Ther. 2012;12(4):503-15). Non hematological indications for rituximab are also not discussed. A Pubmed search was conducted using key words of rituximab, DLBCL, FL, MCL, Burkitt's lymphoma and MALToma. Papers shortlisted for review included randomized control trials and scientific papers discussing CD20.

EXPERT OPINION

In conclusion this paper has critically evaluated the use of rituximab in the treatment mainly of DLBCL, FL and MCL both at diagnosis and relapsed disease, and briefly discuses its use in other subtypes of lymphoma. Rituximab has significantly improved the outcome of patients with B cell NHL, in particular those with DLBCL and FL. Patients usually tolerate the treatment well, and studies have shown it to be a cost effective treatment.

Efficacy of ⁹⁰Yttrium-ibritumomab tiuxetan in relapsed/refractory extranodal marginal-zone lymphoma

We evaluated clinical activity of ⁹⁰Yttrium-ibritumomab (⁹⁰Y-ibritumomab) tiuxetan in extranodal marginal-zone lymphoma. From May 2004 to April 2011, 30 patients affected by relapsed/refractory marginal-zone lymphoma--arisen at any extranodal site--received ⁹⁰Y-ibritumomab tiuxetan at the activity of 0.4 mCi/kg. Median age was 57 years. At time of treatment, 13 out of 30 patients had disseminated disease (stage III/IV). All patients had received a previous treatment with a maximum of 7. Overall response rate was 90%: 23 patients achieved a complete response (77%); partial response occurred in 4 patients (13%), stable disease in 2 patients (7%) and 1 progression (3%). With a median follow-up of 5.3 years, median time to relapse was not reached; 2 patients relapsed after complete response; 18 out of 23 complete responses are still responders after >3 years, 12 of them after >5 years. ⁹⁰Y-ibritumomab tiuxetan seems to be active in patients with extranodal marginal-zone lymphoma relapsed/refractory to conventional treatment including radiotherapy. These results suggest that radioimmunotherapy could represent a possible option for the treatment in this subset of patients.

Marginal zone lymphoma: old, new, targeted, and epigenetic therapies

Marginal zone lymphoma (MZL) is an indolent B-cell lymphoma arising from marginal zone B-cells present in lymph nodes and extranodal tissues. MZL comprises 5-17% of all non-Hodgkin's lymphomas in adults. The World Health Organization categorizes MZL into three distinct types based on their site of impact: (1) splenic marginal zone lymphoma (SMZL); (2) nodal marginal zone lymphoma (NMZL); (3) extranodal mucosa-associated lymphoid tissue (MALT) lymphoma, which can be subdivided into gastric and nongastric. The subgroups of MZL share some common features but are different in their biology and behavior. Owing to the rarity of MZL there are few randomized trials available comparing various treatment options and therefore treatment is controversial, lacking standard guidelines. Treatment should be patient tailored and can range from a 'watchful waiting' approach for asymptomatic patients without cytopenias to surgery or localized radiation therapy. Rituximab in combination with chemotherapy has resulted in longer failure-free survival than chemotherapy alone in patients with SMZL. Helicobacter pylori positive gastric MALT shows a good response rate to triple antibiotic therapy. Newer therapies such as bendamustine, everolimus, lenalidomide, vorinostat and phosphoinositide 3-kinase inhibitors are in clinical trials for patients with relapsed or refractory MZL and have shown promising results. We are presently conducting clinical trials testing the efficacy of the epigenetic activity of cladribine as a hypomethylating agent in combination with the histone deacetylase inhibitor (HDACi) vorinostat and rituximab in patients with MZL. Further studies with the newer agents should be done both in newly diagnosed or relapsed/refractory MZL to streamline the care and to avoid the use of toxic chemotherapies as initial treatment.