Evaluation of the clinical characteristics, management, and prognosis of 103 patients with gastric mucosa-associated lymphoid tissue lymphoma

The diagnosis of gastric mucosa-associated lymphoid tissue (MALT) lymphoma is difficult owing to its non-specific symptoms and various endoscopic findings. Treatments such as radiotherapy (RT) for localized and chemotherapy (CT) for advanced stages of the disease are employed. The aim of the present study was to examine the clinical characteristics and prognostic factors of Helicobacter pylori (H. pylori) eradication (HPE) in patients with gastric MALT lymphoma. The medical records of 103 patients with gastric MALT lymphoma for the period 2001–2013, were analyzed. The 103 median age of the patients was 53 years and the male to female ratio was 1:1. Serum lactate dehydrogenase and β2-microglobulin were within normal range. Macroscopically, the most commonly involved site was the antrum, followed by the corpus and fundus. A total of 97 patients (94%) tested positive for H. pylori. Forty patients (39%) had stage I, 35 patients (35%) had local or distant nodal involvement, 20 of 103 patients had stage IIIE (19%) and 8 of 103 patients had stage IV (7%) disease. Complete remission, after HPE, was achieved in 54 of the 69 patients (78%) that were H. pylori-positive and in 2 of the 4 patients (50%) that were H. pylori-negative. HPE had a superior trend in the H. pylori-positive patients although no significant difference was identified in the two groups (p=0.194). In patients with advanced disease, the 5-year progression-free survival (PFS) and overall survival (OS) estimates were significantly improoved for patients receiving HPE with CT or RT than those receiving CT or RT (p=0.046 and 0.035, respectively). The multivariate analysis revealed that, the advanced stages were independently associated with shorter PFS, and the modified-International Prognostic Index (m-IPI) (≥2) was associated with shorter OS. In conclusion, gastric MALT lymphoma had a favorable outcome with a high OS rate. HPE was an effective treatment for gastric MALT lymphoma. The patients with advanced stages and m-IPI (≥2) had a much worse prognosis.

Infectious Aetiology of Marginal Zone Lymphoma and Role of Anti-Infective Therapy

Marginal zone lymphomas have been associated with several infectious agents covering both viral and bacterial pathogens and in some cases a clear aetiological role has been established. Pathogenetic mechanisms are currently not completely understood. However, the role of chronic stimulation of the host immune response with persistent lymphocyte activation represents the most convincing explanation for lymphoproliferation. Gastric MALT lymphoma is strictly associated with Helicobacter pylori infection and various eradicating protocols, developed due to increasing antibiotic resistance, represent the first line therapy for gastric MALT. The response rate to eradication is good with 80% of response at 1 year; this finding is also noteworthy because it recapitulates cancer cured only by the antibacterial approach and it satisfies the Koch postulates of causation, establishing a causative relationship between Hp and gastric MALT lymphoma. Patients with chronic HCV infection have 5 times higher risk to develop MZL, in particular, an association with splenic and nodal MZL has been shown in several studies. Moreover, there is evidence of lymphoma regression after antiviral therapy with interferon+ribavirin, thus raising hope that newly available drugs, extremely efficient against HCV replication, could improve outcome also in HCV-driven lymphomas. Another case-study are represented by those rare cases of MZL localized to orbital fat and eye conjunctivas that have been associated with Chlamydophila psittaci infection carried by birds. Efficacy of antibacterial therapy against C. psittaci are conflicting and generally poorer than gastric MALT. Finally, some case reports will cover the relationship between primary cutaneous B-cell Lymphomas and Borrelia Burgdorferi.

Underutilization of radiation therapy in early-stage marginal zone lymphoma negatively impacts overall survival

PURPOSE

Multiple population-based studies have suggested increasing omission of radiation therapy in favor of alternative treatment strategies in lymphomas, with an associated negative impact on survival. Radiation therapy has long been considered the standard management for many mucosa-associated lymphoid tissue lymphomas. Thus, we aimed to evaluate patterns of treatment utilization and survival.

METHODS AND MATERIALS

A retrospective analysis based on the National Cancer Database was performed on 22,378 patients with splenic, nodal, or extranodal stage I-II marginal zone lymphoma diagnosed between 1998 and 2012. A logistic regression model was used to assess the association between sociodemographic, tumor, and treatment characteristics and the utilization of radiation therapy. Multivariate propensity score-adjusted Cox proportional hazards models were performed to identify factors independently associated with overall survival (OS).

RESULTS

Of 22,378 patients, 82% had stage I disease, 77% had extranodal mucosa-associated lymphoid tissue lymphoma, 5% had splenic marginal zone lymphoma, and 64% were older than 60 years. Radiation therapy utilization decreased from a peak of 39% in 2007 to 33% in 2011 (P < .001), with a corresponding significant increase in systemic therapy utilization. Radiation therapy was associated with a 5- and 10-year OS of 86.7% and 68.8% compared with 78.3% and 54.3% for no radiation therapy (P < .001). On multivariate propensity score-adjusted survival analysis, radiation therapy remained independently associated with improved OS (hazard of death, 0.75; 95% confidence interval, 0.65-0.85; P < .001).

CONCLUSIONS

Although clinical guidelines endorse radiation therapy as the preferred initial therapy for early-stage nongastric and Helicobacter pylori-negative gastric mucosa-associated lymphoid tissue lymphoma, radiation therapy is underused. Radiation therapy with or without systemic therapy was associated with a significant improvement in OS and should remain standard of care.

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.

Long-term outcomes and patterns of relapse of early-stage extranodal marginal zone lymphoma treated with radiation therapy with curative intent

PURPOSE

To report the long-term outcome and patterns of relapse of a large cohort of marginal zone lymphoma (MZL) patients treated with curative-intent radiation therapy (RT) alone.

PATIENTS AND METHODS

We reviewed the charts of 490 consecutive patients with stage IE or IIE MZL referred between 1992 and 2012 to our institution. Of those, 244 patients (50%) were treated with RT alone. Pathology was confirmed by hematopathologists at our institution. Patient and disease factors were analyzed for association with relapse-free survival (RFS) and overall survival (OS).

RESULTS

Median age of the cohort was 59 years, and median follow-up was 5.2 years. Ann Arbor stage was IE in 92%. Most common disease sites were stomach (50%), orbit (18%), non-thyroid head-and-neck (8%), skin (8%), and breast (5%). Median RT dose was 30 Gy. Five-year OS and RFS were 92% and 74%, respectively. Cumulative incidence of disease-specific death was just 1.1% by 5 years. Sixty patients (24%) developed relapse of disease; 10 were in the RT field. Crude rate of transformation to pathologically confirmed large-cell lymphoma was 1.6%. On multivariable analysis, primary disease site (P=.007) was independently associated with RFS, along with age (P=.04), presence of B-symptoms (P=.02), and International Prognostic Index risk group (P=.03). All disease sites except for head-and-neck had worse RFS relative to stomach.

CONCLUSION

Overall and cause-specific survival are high in early-stage extra-nodal MZL treated with curative RT alone. In this large cohort of 244 patients, most patients did not experience relapse of MZL after curative RT; when relapses did occur, the majority were in distant sites. Stomach cases were less likely to relapse than other anatomic sites. Transformation to large-cell lymphoma was rare.

Modern radiation therapy for extranodal lymphomas: field and dose guidelines from the International Lymphoma Radiation Oncology Group

Extranodal lymphomas (ENLs) comprise about a third of all non-Hodgkin lymphomas (NHL). Radiation therapy (RT) is frequently used as either primary therapy (particularly for indolent ENL), consolidation after systemic therapy, salvage treatment, or palliation. The wide range of presentations of ENL, involving any organ in the body and the spectrum of histological sub-types, poses a challenge both for routine clinical care and for the conduct of prospective and retrospective studies. This has led to uncertainty and lack of consistency in RT approaches between centers and clinicians. Thus far there is a lack of guidelines for the use of RT in the management of ENL. This report presents an effort by the International Lymphoma Radiation Oncology Group (ILROG) to harmonize and standardize the principles of treatment of ENL, and to address the technical challenges of simulation, volume definition and treatment planning for the most frequently involved organs. Specifically, detailed recommendations for RT volumes are provided. We have applied the same modern principles of involved site radiation therapy as previously developed and published as guidelines for Hodgkin lymphoma and nodal NHL. We have adopted RT volume definitions based on the International Commission on Radiation Units and Measurements (ICRU), as has been widely adopted by the field of radiation oncology for solid tumors. Organ-specific recommendations take into account histological subtype, anatomy, the treatment intent, and other treatment modalities that may be have been used before RT.

Clinical aspects of malt lymphomas

Extranodal marginal zone lymphoma of the mucosa-associated lymphoid tissue (MALT) is an indolent lymphoma arising in extranodal sites. Several infectious agents and autoimmune disorders have been implicated in its pathogenesis. The stomach represents the most common and best-studied organ involved by MALT lymphoma and its development is strongly associated with Helicobacter pylori (Hp) infection. MALT lymphomas are characterized by an indolent clinical course and excellent survival in most cases, independently of the treatment delivered. Recent progress in the knowledge of the etiology and the cellular and molecular pathological events related to MALT lymphomas allowed us to improve our clinical understanding of this disease entity and to better define treatment strategies.

Radical surgery may be not an optimal treatment approach for pulmonary MALT lymphoma

Primary pulmonary MALT lymphoma is a rare disease, and no standard treatments have been defined yet. In this study, 38 consecutive patients from single center were reviewed. Among 25 patients with localized disease, radical surgery were performed in 12 patients, and the other 13 patients had chemotherapy combined with (7 patients) or without (6 patients) radiotherapy. No significant difference in overall survival (OS) was found between patients who received surgery or not; however, patients treated with chemotherapy had superior progression-free survival (PFS) than those treated with upfront surgery (P = 0.032). Among the 12 patients who received radical surgery, 7 were given adjuvant chemotherapy and 1 patient had consolidation radiotherapy. No significant differences in PFS and OS exist between those who received adjuvant treatment or not (P > 0.05). For patients who received chemotherapy, PFS and OS were significantly better for those treated with cyclophosphamide-based therapy than fludarabine-based therapy. At a median follow-up time of 61.1 months, 5- and 10-year PFS rate was 70.0 and 43.0 %, respectively, and 5- and 10-year OS rate was both 81.0 %. In conclusion, we confirmed the indolent behavior and favorable outcome of this disease. In order to preserve lung function and reduce the risks associated with surgery, radiotherapy or rituximab in combination with alkylating drug-based chemotherapy should be considered as first-line option for pulmonary MALT lymphoma.

Diffuse large B-cell lymphoma: sites of extranodal involvement are a stronger prognostic indicator than number of extranodal sites in the rituximab era

The National Comprehensive Cancer Network (NCCN) International Prognostic Index (IPI) is an enhanced prognostic tool that has identified some specific extranodal sites as a poor prognostic factor. We retrospectively analyzed 148 Taiwanese patients with newly diagnosed diffuse large B-cell lymphoma receiving rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP)-like regimens from January 2001 to December 2010 at the Tri-Service General Hospital. In univarate analysis, ≥ 2 extranodal involved sites had no significant prognostic relevance (p = 0.108), although extranodal involvement of the lung/pleura, liver, lower urinary tract or bone marrow was a statistically significant poor prognostic factor (p < 0.001). In multivariate analysis, specific extranodal sites had a stronger predictive value for poor prognosis (relative risk 3.654, 95% confidence interval 1.514-8.815, p = 0.004) compared with the number of extranodal sites involved. This finding suggests that specific extranodal involved sites have prognostic value in the R era.

Management of the marginal zone lymphomas

Marginal zone lymphomas (MZL) represent around 8 % of all non-Hodgkin lymphomas. During the last decades a number of studies have addressed the mechanisms underlying the disease development. Extranodal MZL lymphoma usually arises in mucosal sites where lymphocytes are not normally present from a background of either autoimmune processes, such as Hashimoto thyroiditis or Sjögren syndrome or chronic infectious conditions. In the context of a persistent antigenic stimulation, successive genetic abnormalities can progressively hit a B-cell clone among the reactive B-cells of the chronic inflammatory tissue and give rise to a MALT lymphoma. The best evidence of an etiopathogenetic link is available for the association between Helicobacter pylori-positive gastritis and gastric MALT lymphoma. Indeed, a successful eradication of this micro-organism with antibiotics can be followed by gastric MALT lymphoma regression in more than 2/3 of cases. Other microbial agents have been implicated in the pathogenesis of MZL arising in the skin (Borrelia burgdorferi), in the ocular adnexa (Chlamydophila psittaci), and in the small intestine (Campylobacter jejuni). The prevalence of hepatitis C virus (HCV) has also been reported higher in MZL patients (particularly of the splenic type) than in the control population, suggesting a possible causative role of the virus. In non-gastric MALT lymphoma and in splenic MZL the role of the antimicrobial therapy is, however, less clear. This review summarizes the recent advances in Marginal Zone Lymphomas, addressing the critical points in their diagnosis, staging and clinical management.

Management of gastric mucosa-associated lymphoid tissue lymphoma

Extranodal marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT) type represent 7-8% of all B cell lymphomas and up to 50% of primary gastric lymphomas and can arise at any extranodal site. The most common manifestation is the stomach, which is almost invariably associated with a chronic Helicobacter pylori infection. The diagnosis is based on the histopathological evaluation of multiple gastric biopsies in accordance with the current WHO classification. The mainstay of therapy is H. pylori eradication, which must be delivered to all gastric MALT lymphoma patients, independent of stage. In patients who do not achieve lymphoma regression following antibiotic therapy, irradiation and/or systemic oncological therapies should be applied, depending on the stage of the disease. Radiotherapy might be the preferred option for localized stage. However, in the presence of disseminated or advanced disease, chemotherapy and/or immunotherapy with the anti-CD 20 antibody rituximab is the treatment of choice, but no standard chemotherapy has been defined so far. Gastric MALT lymphomas have a limited tendency to distant spreading and to histological transformation and thus MALT lymphoma usually has a favorable outcome, with an overall survival rate at 5 years of more than 85%.