Rituximab plus subcutaneous cladribine in patients with extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue: a phase II study by the Arbeitsgemeinschaft Medikamentose Tumortherapie

Long-Term Clinical Outcomes in Treatment-Naïve Patients With Orbital Adnexal Mucosa-Associated Lymphoid Tissue Lymphoma: A Single-Center Study

Ocular adnexal mucosa-associated lymphoid tissue (MALT) lymphoma (OAML) is the most common type of ocular lymphoma with a higher prevalence in Asia than in Western countries. OAML represents 1%–2% of all non-Hodgkin’s lymphoma, 5%–15% of extranodal lymphomas, and approximately 55% of orbital malignancies. “Watch and wait” after biopsy or surgical resection, radiation therapy, and systemic treatment, including antibiotics administration and chemotherapy with various combinations of regimens can be considered for OAML treatment. Radiotherapy is adapted for limited-stage disease with excellent clinical outcomes of 85–100% complete remission and relatively superior local control efficacy and treatment duration. In contrast, chemotherapy has rarely been tested as frontline therapy. Nonetheless, several studies have reported a favorable response and long duration of progression-free survival using chemotherapy adaptations. When the disease involves both eyes or spreads beyond the conjunctiva, the risk of recurrence increases and limited-stage OAML has a recurrence rate of approximately 25% following radiotherapy only. Therefore, although recent consensus in the literature is that patients with limited-stage OAML recommended treating with radiation, physicians may choose the treatment modality not only by its efficiency but also by its adverse events profile and patients’ well-being. Herein, we present a large single-center study on OAML that included 292 patients who were followed up for up to 237 months. We collected and analyzed real-world data focusing on treatment outcomes and the role of radiotherapy as frontline therapy, and aimed to compare outcomes and complication profiles of chemotherapy, especially in limited-stage OAML, to identify an optimal treatment strategy.

Refractoriness to rituximab-based therapy and elevated serum B2-microglobulin predict for inferior survival in marginal zone lymphoma

Short responses to immunochemotherapy predict for an inferior OS in follicular lymphoma. We set out to determine whether this is also the case in marginal zone lymphoma. A group of 139 marginal zone lymphoma (MZL) patients treated with front-line immuno- or immunochemotherapy (I/ICT) were categorized into I/ICT-refractory (non-response or relapse/progression within six months of treatment response assessment) or I/ICT-sensitive. Twenty-three patients (17%) were refractory. Refractory patients had inferior OS (4-yr probabilities of 57% vs. 83%, p = .0003) as did those with beta2-microglobulin (B2M)>3 mg/L (4-yr probabilities of 80% vs. 100%, p = .0029). On multivariable analysis they both showed a borderline significant correlation with OS (p = .06 and .07, respectively). B2M > 3 mg/L was also an adverse prognostic factor for progression-free survival in both univariable (4-yr probability of 61% vs. 83%, p = .02) and multivariable analysis (HR 2.9, p = .02). In conclusion, B2M and refractoriness to I/ICT may identify patients with MZL at higher risk of inferior survival.

Rituximab, cladribine, and cyclophosphamide (RCC) induction with rituximab maintenance in chronic lymphocytic leukemia: PALG - CLL4 (ML21283) trial

OBJECTIVES

PALG CLL4 is the first, randomized, phase IIIb study with rituximab, cladribine, and cyclophosphamide (RCC) induction and subsequent maintenance with rituximab in previously untreated chronic lymphocytic leukemia (CLL) patients.

METHODS

The induction treatment consisted of 6 RCC cycles regimen. Patients with complete response (CR) or partial response (PR) after an induction phase were randomized into a maintenance arm with rituximab or an observational arm.

RESULTS

In the intention-to-treat population, 97 patients completed the induction phase with an overall response rate (ORR) of 73.2% (CR 22.7%, PR 50.5%). Subsequently, 66 patients were randomized into the rituximab maintenance arm (n = 33) or the observational arm (n = 33). CR rates were 57.1% in the maintenance group vs 50% in the observational group. PFS was significantly longer in the rituximab maintenance vs the observational arm (P = .028). The multivariate Cox model indicated that del17p (P = .006) and elevated beta-2-microglobulin (P = .015) significantly increased the hazard ratio (HR) of progression, whereas the presence of CD38 (P = .013) significantly decreased it; maintenance therapy with rituximab (P < .0001) significantly decreased the HR of disease progression.

CONCLUSIONS

The study confirmed the high efficacy and acceptable safety profile of induction therapy with RCC and maintenance therapy with rituximab in previously untreated patients with CLL.

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

There is no consensus about the best treatment option for patients with HP-negative gastric MALT lymphomas or persistent disease after HP eradication.We have investigated fludarabine and mitoxantrone with rituximab (R-FM) as first-line treatment. A cohort of 13 patients was analyzed. Induction treatment consisted of fludarabine (25 mg/m² i.v. on days 2 to 4), mitoxantrone (10 mg/m² i.v. on day 2), and rituximab (375 mg/m² i.v. on day 1), for up to six cycles every 28 days. All patients achieved a complete remission, a median of four cycles was given. Treatment-related toxicities were mainly hematologic, with grade 3-4 neutropenia observed in 11/13 patients (84.6%). One patient had grade 3 febrile neutropenia, two patients developed prolonged pancytopenia (15%), and one patient experienced CMV reactivation at 2 months. After a median follow-up of 84 months, 1/13 had disease relapse and received total gastrectomy; estimated 10-year progression-free survival and overall survival were 92.4 and 100%, respectively. Our study suggests R-FM regimen has a high long-term efficacy for untreated HP-negative gastric MALT lymphoma patients and HP-positive patients who failed HP eradication. The elevated incidence of grade 3-4 hematological toxicity, yet manageable, makes this treatment less safe compared to rituximab in combination with chlorambucil or bendamustine.

Phase 2 Open-Label Study of Bortezomib, Cladribine, and Rituximab in Advanced, Newly Diagnosed, and Relapsed/Refractory Mantle-Cell and Indolent Lymphomas

BACKGROUND

Mantle-cell lymphoma (MCL) and indolent non-Hodgkin lymphoma (iNHL) are incurable heterogeneous diseases characterized by relapse. There is a need for newer treatments in MCL and iNHL, especially in the relapsed/refractory (R/R) setting. We therefore investigated the novel combination of bortezomib (Velcade), cladribine, and rituximab (VCR) in front-line and R/R settings in MCL and iNHL (NCT00980395).

PATIENTS AND METHODS

Eligible patients included adults with biopsy-proven CD20-positive MCL and iNHL who met the criteria for treatment. Rituximab 375 mg/m² intravenous (IV) day 1, cladribine 4 mg/m² IV days 1 to 5, and bortezomib 1.3 mg/m² IV days 1 and 4 were administered every 28 days for 6 cycles.

RESULTS

Twenty-four patients were enrolled onto the study with a median follow-up of 38.5 months. Median age was 66.5 years, and 46% had MCL. The most common adverse events were hematologic, with febrile neutropenia in 3 patients. Neuropathy was noted in 17% of patients, of which 8% was grade 3 or above. The overall response rate was 92%. For the entire cohort, and for MCL patients, the median progression-free survival and the median overall survival were not reached. The 2-year progression-free survival was 82% for the MCL group and 54% for the iNHL group; it was 80% for treatment-naive patients and 57% for R/R patients.

CONCLUSION

VCR is effective in MCL and iNHL. Although hematologic toxicity can be an issue, this study demonstrates a high response rate to a novel combination and provides an alternative option in transplant-ineligible R/R MCL and iNHL.

Extranodal Marginal Zone Lymphoma: No Longer Just a Sidekick

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors’ suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice.

A 51-year-old healthy female with good performance status presented for gynecologic surgery for a benign condition. A preprocedure chest x-ray showed a right lower lobe infiltrate. A subsequent computed tomography (CT) scan of the chest with contrast revealed a large consolidative right lower lobe mass with surrounding inflammation ( Fig 1A ). Bronchoscopy with biopsy revealed a low-grade lymphoma with the following immunophenotype: CD45+, CD20+, BCL2+, CD10 negative, CD5 negative, cyclin D1 negative, and Ki-67 index of less than 5%. Morphology and immunohistochemistry were most consistent with pulmonary extranodal marginal zone lymphoma (ENMZL; Fig 2 ). The patient was asymptomatic and denied fevers, sweats, weight loss, shortness of breath or dyspnea on exertion, or cough. Her history was notable for exposure to parrots over several months before presentation. Complete staging with a CT of the chest, abdomen, and pelvis with contrast redemonstrated disease that was localized to the chest with mild compression of the pulmonary vasculature but no other evidence of lymphoma. She was referred to discuss management of stage IAE pulmonary ENMZL lymphoma.

A single center experience: rituximab plus cladribine is an effective and safe first-line therapy for unresectable bronchial-associated lymphoid tissue lymphoma

BACKGROUND

Bronchial-associated lymphoid tissue (BALT) lymphoma is a relatively rare form of B-cell non-Hodgkin lymphoma (B-NHL). To date, the standard systemic treatment for this disease is still under debate, and few data are accessible for newly diagnosed unresectable BALT lymphoma presented with advanced disease. The combination of rituximab (R) and cladribine (2-CdA) has shown some activity in indolent B-NHL, but its usage has not been tested in disseminated BALT lymphoma so far.

METHODS

An observational retrospective study was performed on homogeneous data of 8 patients with biopsy-proven stage IV BALT lymphoma to assess the efficacy and the safety of R-2-CdA therapy. All but one of the patients received six courses of R-2-CdA regimen consisted of rituximab 375 mg/m² IV day 1 and cladribine 0.1 mg/kg IV days 1-4 every 21 days; one patient completed 4 cycles and received additional R maintenance.

RESULTS

A high overall response rate (ORR) was observed (100%), with 2 patients (25%) achieved a complete remission (CR), the remaining (75%) a partial response. Improvement of pulmonary function was observed in all tested patients. Grade 3 and 4 toxicities were leukocytopenia and neutropenia in 3 patients (37.5%), diarrhea in one (12.5%). Estimated two-year progression-free survival (PFS) and 2-yr overall survival (OS) were 80.0% (95% CI, 20.3-96.7%) and 100%, respectively.

CONCLUSIONS

R-2-CdA therapy demonstrated high activity and tolerable toxicity in chemotherapy-naïve patients with unresectable BALT lymphoma of advanced stage. Although further large-scale study is needed for consolidation, R-2-CdA regimen could be a good first-line therapy option for patients with unresectable BALT lymphoma.

Ocular adnexal marginal zone lymphoma: Clinical presentation, pathogenesis, diagnosis, prognosis, and treatment

Ocular adnexal marginal zone lymphoma (OAML) represents 1-2% of all non Hodgkin lymphomas. In the last few years many advances in understanding the pathogenesis and the molecular basis involved in its development have been done. Many potential risk factors have been proposed; a dysregulation of immune response in association with a chronic antigenic stimulation, have been hypothesized as possible pathogenic mechanism. In particular, Chlamydia psittaci infection has been related to OAML arising, and eradicating antibiotic therapy has been addressed as a safe and cost-effective approach. Management of OAML is still heterogeneous and matter of debate. There is no consensus about the best upfront treatment and therapeutic decision should take into account several patient-, lymphoma- and treatment-related factors. Novel agents and chemotherapy-free strategies are being investigated to reduce side effects and improve tumor control. This review is focused in recent knowledge improvements in this lymphoma.

Marginal zone lymphoma in elderly and geriatric patients

Approximately 50% of patients with newly diagnosed marginal zone lymphoma (MZL) are of advanced age. For the three subtypes of MZL (extranodal MZL of mucosa-associated lymphoid tissue, splenic MZL, nodal MZL), the median age at diagnosis is around 65-70 years. Due to the lack of larger studies in MZL, little is known of the prevalence of comorbidity, polypharmacy, or geriatric syndromes in older patients with MZL. The impact of these concurrent conditions on the tolerability and feasibility of diagnostic or therapeutic procedures used in MZL has not been specifically investigated. However, some extrapolations can be made from other studies in cancer, thereby raising questions about potential benefits of geriatric assessment in older patients with MZL. Core of this article is a review of recommended diagnostic and therapeutic procedures in MZL in light of potential barriers and complications that might be encountered in elderly and geriatric patients with MZL.

Clinicopathologic characteristics and treatment of marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma)

Extranodal marginal zone lymphoma of the mucosa-associated lymphoid tissue (MALT lymphoma) accounts for 7% to 8% of newly diagnosed lymphomas. Because of its association with infectious causes, such as Helicobacter pylori (HP) or Chlamydophila psittaci (CP), and autoimmune diseases, it has become the paradigm of an antigen-driven malignancy. MALT lymphoma usually displays an indolent course, and watch-and-wait strategies are justified initially in a certain percentage of patients. In patients with gastric MALT lymphoma or ocular adnexal MALT lymphoma, antibiotic therapy against HP or CP, respectively, is the first-line management of choice, resulting in lymphoma response rates from 75% to 80% after HP eradication and from 33% to 65% after antibiotic therapy for CP. In patients who have localized disease that is refractory to antibiotics, radiation is widely applied in various centers with excellent local control, whereas systemic therapies are increasingly being applied, at least in Europe, because of the potentially systemic nature of the disease. Therefore, the objective of this review is to briefly summarize the clinicopathologic characteristics of this distinct type of lymphoma along with current data on management strategies.

Pulmonary mucosa-associated lymphoid tissue lymphoma revisited

This general review sought to clarify the pathophysiological, diagnostic, prognostic, and therapeutic features of pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma.MALT lymphoma is the most common pulmonary B-cell lymphoma, which usually occurs in the context of acquired MALT. The disease is slow-growing with an asymptomatic chronic alveolar opacity visible on radiography. Diagnosis requires tissue samples that should be retrieved using minimally invasive techniques, such as bronchoscopy or computed tomography-guided biopsies. The pathophysiology includes cytogenetic abnormalities and autoimmune diseases, whereas an association with a chronic pulmonary infection is still suspected but not yet demonstrated. Disease prognosis is typically excellent and the current available treatments are discussed in this review, including the decision not to treat, surgery, and single- or double-agent chemotherapy.

Long-term safety and activity of cladribine in patients with extranodal B-cell marginal zone lymphoma of the mucosa-associated lymphoid tissue (MALT) lymphoma

The purine analogue 2-chloro-deoxyadenosine (2-CDA, cladribine) +/- rituximab has been successfully tested in mucosa-associated lymphoid tissue lymphoma (MALT lymphoma) patients. However, studies using cladribine in other indications have reported the potential for prolonged hematological side effects and secondary hematologic and non-hematologic malignancies. To date, there have been no data on long-term effects of cladribine in MALT lymphoma patients. We have analyzed a large number of 49 patients treated with cladribine at our institution 1997-2011. All patients were treated within clinical trials and had undergone a standardized follow-up protocol minimizing a potential bias in the detection of late sequels and relapses. After a median follow-up time of 61 months (interquartile range: 43-72) for 49 analyzed patients, 35 (71%) are alive, while 14 (29%) have died. In the entire collective, three cases (6%) of prolonged pancytopenia including manifest myelodysplastic syndrome in one patient (2%), three cases (6%) of secondary lymphoid malignancies, and five cases (10%) of non-hematologic cancers were documented. In terms of outcome, 42/49 (86%) patients responded to cladribine-containing treatment, and only 10/42 (24%) responding patients needed further treatment after a median time to progression of 14 months (interquartile range, 8-34). Currently, 25/35 (71%) patients being alive are in ongoing complete remission and 2/35 (6%) in ongoing stable disease, respectively. Eight patients (23%) are free of lymphoma after second-line therapy, with the median overall survival not having been reached. Our data suggest that cladribine might be safely applied in patients with MALT lymphoma, also in terms of long-term toxicities. These data also confirm the potential of cladribine to induce durable remissions. Copyright © 2015 John Wiley & Sons, Ltd.

The origin and targeting of mucosa-associated lymphoid tissue lymphomas

PURPOSE OF REVIEW

Extranodal mucosa-associated lymphoid tissue (MALT lymphoma) is a distinct clinical-pathological entity that can be distinguished from other lymphomas by a number of unique features, including their location in various extranodal sites, being preceded by chronic inflammatory or infection processes; a characteristic histopathological picture; and the presence of exclusive chromosomal translocations which increase MALT1 proteolytic activity to promote constitutive NF-κB signaling and eventually drive lymphomagenesis.

RECENT FINDINGS

This review explores the major molecular and cellular events that participate in MALT lymphoma pathogenesis, focusing on gastric MALT lymphoma as a model of chronic inflammation-induced tumor development. In addition, the pivotal roles of activated MALT1 protease, its substrate TNFAIP3/A20, and the MyD88 adaptor protein in abnormally triggering downstream NF-κB pathway are overviewed. These new insights provide a mechanistic basis for using novel therapies targeting MALT1 protease or IRAK4 kinase activities. Finally, the putative cellular origin of MALT lymphomas is also discussed.

SUMMARY

Over the last decade, unraveling the biological complexity of MALT lymphomas has shed light on the fundamental cellular and molecular aspects of the disease that are to be translated into clinical diagnostics and therapy.

Chemoimmunotherapy for Mucosa-Associated Lymphoid Tissue-Type Lymphoma: A Review of the Literature

BACKGROUND

Biological treatments, chemoimmunotherapy, and radiotherapy are associated with excellent disease control in both gastric and extragastric mucosa-associated lymphoid tissue (MALT) lymphomas. Systemic treatment approaches with both oral and i.v. agents are being increasingly studied, not only for patients with disseminated MALT lymphoma, but also for those with localized disease. To date, however, recommendations for the use of available systemic modalities have not been clearly defined.

MATERIALS AND METHODS

The present report reviews the current data on systemic treatment options for patients with MALT lymphoma and provides recommendations for their use in everyday practice.

RESULTS

Different chemotherapeutic agents, including anthracyclines, alkylators, and purine analogs, have been successfully tested in patients with MALT lymphoma. Reducing side effects while maintaining efficacy should be the main goal in treating these indolent lymphomas. From the data from the largest trial performed to date, the combination of chlorambucil plus rituximab (R) appears to be active as first-line treatment. Similarly, R-bendamustine also seems to be highly effective, but a longer follow-up period is needed. R-monotherapy results in lower remission rates, but seems a suitable option for less fit patients. New immunotherapeutic agents such as lenalidomide (with or without rituximab) or clarithromycin show solid activity but have not yet been validated in larger collectives.

CONCLUSION

Patients with MALT lymphoma should be treated within prospective trials to further define optimal therapeutic strategies. Systemic treatment is a reasonable option with potentially curative intent in everyday practice. Based on the efficacy and safety data from available studies, the present review provides recommendations for the use of systemic strategies.

New pharmaceutical treatment of gastric MALT lymphoma: anti-angiogenesis treatment using VEGF receptor antibodies and celecoxib

In addition to eradication of Helicobacter pylori, chemotherapy with anticancer agents, and radiation therapy, the treatment with molecular target drugs including rituximab, a CD20 antagonist, is one of the promising new regimens. The mucosa-associated lymphoid tissue (MALT) lymphoma is histologically characterized by rich distribution of the microvascular network consisting of the immature capillaries, lymphatics and venules, and this microvascular network could be the target of the new pharmacotherapy in addition to the direct action on the accumulated B lymphocytes. We have established the animal model of the gastric MALT lymphoma by the Helicobacter heilmannii (H. heilmannii) peroral infection of C57BL/6 mice. The disease induced by this model is very similar to the human counterpart, because of the lymphoepithelial lesion characteristic of the human MALT lymphoma as well as the rich vascularization and localization of vascular endothelial growth factor (VEGF) and its receptors, Flt-1, Flk-1 and Flt-4. By administering VEGF receptor antibodies or celecoxib, one of the cyclooxygenase 2 inhibitors, we were able to induce a significant decrease in the size of the tumor and the apoptotic changes of the endothelial cells of the microvascular network. These antiangiogenic strategies were suggested to be candidates for the new pharmacological treatment of gastric MALT lymphoma, when other treatments are not effective.

Clinical features, treatment and outcome of mucosa-associated lymphoid tissue (MALT) lymphoma of the ocular adnexa: single center experience of 60 patients

Background

Orbital marginal zone B-cell lymphoma (OAML) constitutes for the most frequent diagnosis in orbital lymphoma. Relatively little data, however, have been reported in larger cohorts of patients staged in a uniform way and no therapy standard exists to date.

Material and Methods

We have retrospectively analyzed 60 patients diagnosed and treated at our institution 1999–2012. Median age at diagnosis was 64 years (IQR 51–75) and follow-up time 43 months (IQR 16–92). All patients had undergone uniform extensive staging and histological diagnosis was made by a reference pathologist according to the WHO classification.

Results

The majority of patients presented with stage IE (n = 40/60, 67%), three had IIE/IIIE and the remaining 17 stage IVE. Seven patients with IVE had bilateral orbital disease whereas the others showed involvement of further organs. Treatment data were available in 58 patients. Local treatment with radiotherapy (14/58, 24%) or surgery (3/58, 5%) resulted in response in 82% of patients. A total of 26 patients (45%) received systemic treatment with a response rate of 85%. Nine patients received antibiotics as initial therapy; response rate was 38%. Watchful-waiting was the initial approach in 6/58 patients. In total 28/58 patients (48%) progressed and were given further therapy. Median time-to-progression in this cohort was 20 months (IQR 9–39). There was no difference in time-to-progression after first-line therapy between the different therapy arms (p = 0.14). Elevated beta-2-microglobulin, plasmacytic differentiation, autoimmune disorder and site of lymphoma were not associated with a higher risk for progress.

Conclusion

Our data underscore the excellent prognosis of OAML irrespective of initial therapy, as there was no significant difference in time-to-progression and response between local or systemic therapy. In the absence of randomized trials, the least toxic individual approach should be chosen for OAML.

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.

Treatment of gastric MALT lymphoma with a focus on Helicobacter pylori eradication

Mucosa-associated lymphoid tissue (MALT) lymphoma is an indolent disease with a prolonged clinical course that most often involves the stomach. Clinically, for Helicobacter pylori-positive low-grade MALT lymphoma, antibiotics have been used as the first-line treatment. The recommended anti-Helicobacter triple drug therapy includes a proton pump inhibitor (or ranitidine bismuth citrate), clarithromycin, and amoxicillin (or metronidazole). Considering the difficulty involved with confirming histological remission and the lack of systemic endoscopic follow-up, much work remains to be done in this area. This review describes MALT lymphoma treatment methods and their efficacy, highlights results of the newest studies, and proposes avenues toward future developments in this field.

Helicobacter pylori infection, chronic inflammation, and genomic transformations in gastric MALT lymphoma

Nowadays, it is believed that the main role in the development of gastric mucosa-associated lymphoid tissue (MALT) lymphoma plays Helicobacter pylori infection. This world-wide distributed bacteria is in charge of most cases of not only upper gastrointestinal tract disorders but also some of extragastric problems. Constant stimulation of the immune system causes a B-lymphocytes proliferation, which is considered to be responsible for the neoplastic transformation. On the other hand, there are 10%–20% of patients who do not respond to Helicobacter pylori eradication treatment. This group has often a chromosome translocation, which suggests that there is another unknown, so far, pathogenetic mechanism of MALT lymphoma. Majority of genetic abnormalities are connected with nuclear factor-κB (NF-κB) pathway, which activates the uncontrolled proliferation of neoplastic cells. Translocations already described in studies are t(11;18)(q21;q21), which is the most common, t(14;18)(q32;q21), t(14;18)(q32;q21), and t(3;14)(p14.1;q32). This non-Hodgkin's lymphoma is an indolent type originated outside lymph nodes. In more than 50% of cases, it occurs in the stomach. Occasionally, it can be found in salivary and thyroid gland, lung, breast, bladder, skin, or any other place in the human body. This paper is a review of the current knowledge on etiology, pathogenesis, treatment, and follow-up of gastric MALT lymphoma.