Complete remission of primary high-grade B-cell gastric lymphoma after cure of Helicobacter pylori infection

[Gastric MALT lymphoma - from pathogenetic insights to consequent deescalation of therapy]

Gastric MALT- (mucosa-associated-lymphoid-tissue) lymphoma represents the most frequent gastrointestinal lymphoma. For decades, surgery and later on radiation and chemotherapy were regarded as established therapy. Some 30 years ago, the pathogenetic role of Helicobacter pylori infection for the development of gastric MALT-lymphoma became evident. During the following years, the pathogenetic insights were consequently implemented into clinical medicine. This lead to a radical change of the therapeutic approach to these lymphoma. Nowadays, Helicobacter pylori eradication is the internationally established therapy of first choice. It is followed by lymphoma regression in most cases. The long-term prognosis of patients after exclusive eradication therapy is excellent, even if endoscopic and/or histological residuals persist and a watch-and-wait strategy is favored.The pathogenetic insights und their clinical application implicated a consequent deescalation of therapy of gastric MALT-lymphoma. This review summarizes the single steps of this development and gives a recommendation for the actual management of patients with gastric MALT lymphoma.

Limited-stage diffuse large B-cell lymphoma: current management and challenges

Twenty-five to thirty per cent of diffuse large B-cell lymphoma (DLBCL) presents as limited stage (I-II). Prognosis is generally excellent with four to six cycles of R-CHOP alone (rituximab, cyclophosphamide, vincristine, doxorubicin, prednisolone) or combined-modality therapy with three or four cycles and involved-site radiotherapy (RT). There is growing interest in optimising algorithms to retain disease control whilst minimising long-term toxicity, with several recent studies focusing on the safety of abbreviating chemotherapy and omitting RT in low-risk patients and the utility of PET-based response-adapted approaches. As these studies are limited to younger patients without risk factors, application of similar approaches in elderly or higher-risk patients is hampered by a lack of evidence. Whilst there has been a move away from using RT in low-risk patients, it remains a useful adjunct in specific situations. Current evidence cannot exclude a clinically meaningful benefit from RT even in low-risk patients and, given the low expected toxicity from modern RT techniques, a risk-benefit assessment should be individualised and considered in a multidisciplinary fashion. The optimal approach for extranodal limited-stage DLBCL (~40% of cases) varies according to site of origin. Herein we discuss the latest clinical trial evidence and how this can be applied in routine practice.

Multidimensional role of bacteria in cancer: Mechanisms insight, diagnostic, preventive and therapeutic potential

The active role of bacteria in oncogenesis has long been a topic of debate. Although, it was speculated to be a transmissible cause of cancer as early as the 16th-century, yet the idea about the direct involvement of bacteria in cancer development has only been explored in recent decades. More recently, several studies have uncovered the mechanisms behind the carcinogenic potential of bacteria which are inflammation, immune evasion, pro-carcinogenic metabolite production, DNA damage and genomic instability. On the other side, the recent development on the understanding of tumor microenvironment and technological advancements has turned this enemy into an ally. Studies using bacteria for cancer treatment and detection have shown noticeable effects. Therapeutic abilities of bioengineered live bacteria such as high specificity, selective cytotoxicity to cancer cells, responsiveness to external signals and control after ingestion have helped to overcome the challenges faced by conventional cancer therapies and highlighted the bacterial based therapy as an ideal approach for cancer treatment. In this review, we have made an effort to compile substantial evidence to support the multidimensional role of bacteria in cancer. We have discussed the multifaceted role of bacteria in cancer by highlighting the wide impact of bacteria on different cancer types, their mechanisms of actions in inducing carcinogenicity, followed by the diagnostic and therapeutic potential of bacteria in cancers. Moreover, we have also highlighted the existing gaps in the knowledge of the association between bacteria and cancer as well as the limitation and advantage of bacteria-based therapies in cancer. A better understanding of these multidimensional roles of bacteria in cancer can open up the new doorways to develop early detection strategies, prevent cancer, and develop therapeutic tactics to cure this devastating disease.

Update on B-cell lymphoproliferative disorders of the gastrointestinal tract

The gastrointestinal (GI) tract is home to a significant portion of the immune system, which interacts daily with the antigenic milieu of its contents. Therefore, the presence of white blood cells within the walls of the GI tract upon histologic examination is a familiar sight on GI biopsies-both in health and disease. The GI tract is the most common site of extranodal lymphomas, most of which are B-cell neoplasms. Here, we review common and uncommon B-cell neoplasms of the GI tract - extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma), mantle cell lymphoma, duodenal-type follicular lymphoma, diffuse large B-cell lymphoma, plasmablastic lymphoma, EBV-positive mucocutaneous ulcer, and post-transplant lymphoproliferative disorders - with special focus on literature published during the past five years. Along with the other articles in this edition of Seminars in Diagnostic Pathology, it is the authors' hope that this review proves to be a useful resource in the workup of the array of hematopoietic processes that can involve the GI tract.

The Multifaceted Role and Utility of MicroRNAs in Indolent B-Cell Non-Hodgkin Lymphomas

Normal B-cell development is a tightly regulated complex procedure, the deregulation of which can lead to lymphomagenesis. One common group of blood cancers is the B-cell non-Hodgkin lymphomas (NHLs), which can be categorized according to the proliferation and spread rate of cancer cells into indolent and aggressive ones. The most frequent indolent B-cell NHLs are follicular lymphoma and marginal zone lymphoma. MicroRNAs (miRNAs) are small non-coding RNAs that can greatly influence protein expression. Based on the multiple interactions among miRNAs and their targets, complex networks of gene expression regulation emerge, which normally are essential for proper B-cell development. Multiple miRNAs have been associated with B-cell lymphomas, as the deregulation of these complex networks can lead to such pathological states. The aim of the present review is to summarize the existing information regarding the multifaceted role of miRNAs in indolent B-cell NHLs, affecting the main B-cell subpopulations. We attempt to provide insight into their biological function, the complex miRNA-mRNA interactions, and their biomarker utility in these malignancies. Lastly, we address the limitations that hinder the investigation of the role of miRNAs in these lymphomas and discuss ways that these problems could be overcome in the future.

Gastric Diffuse Large B-Cell Lymphoma: A Single-Center 9-Year Experience

Gastric diffuse large B cell lymphoma (DLBCL) represents the majority of all gastric lymphomas. We report a series of gastric DLBCL diagnosed and treated in a single center, between 2010 and 2018 (included). We retrospectively analyzed the population demographic features, treatment outcomes and survival. One-hundred-and-one patients were studied, 50.5% males and median age of 64 years [23–94]. Lugano staging was I in 16.8%, II1 in 20.8%, II2 in 10.9%, IIE in 13.9% and IV in 34.7% of cases. Twenty percent had Helicobacter pylori infection. R-CHOP-like therapy was used as first line in 96.9% of the patients. A complete response was achieved in 80% after first line therapy. At 3-years of follow-up (FU), 54% were in complete remission. The mean FU time was 73.6 months. Median overall survival and median progression free survival were not reached. We identified seven factors with negative impact in survival: age above 65 years-old (p < 0.01), ECOG 2–3 (p < 0.01), B symptoms (p = 0.001), bulky disease (p = 0.003), IPI 3–4 (p = 0.001), more than 3 treatment lines (p < 0.01), absence of response to first line treatment (p < 0.01). This study demonstrates that gastric DLBCL is a potentially curable disease with R-CHOP-like therapy, entailing long term survival and comparing well with other published series.

Progression of Primary Gastric Diffuse Large B-Cell Lymphoma after Helicobacter pylori Eradication

In Helicobacter pylori−positive, localized primary gastric diffuse large B-cell lymphoma (DLBCL), an increasing number of reports have recently been published on the effectiveness of H. pylori eradication (HPE). However, HPE treatment strategies for gastric DLBCL, including its indications, have yet to be examined. No detailed report has been published on a case of gastric DLBCL unsuccessfully treated by HPE. A 64-year-old female and a 70-year-old male were pathologically diagnosed with chronic active gastritis and mucosa-associated lymphoid tissue lymphoma, respectively. Both patients were positive for H. pylori, so HPE was employed. The disease progressed within 1 year, and both patients were pathologically diagnosed with DLBCL by endoscopic biopsy. On reviewing the first pathology slide, both patients were diagnosed with DLBCL. That is, the 2 patients had primary gastric DLBCL; however, they exhibited progressive disease after HPE. This failure of HPE treatment may be due to the initial lymphomas being multiplex ulcerative lesions. In both cases, complete remission was achieved by chemotherapy (plus radiation therapy) without recurrence for more than 3 years.

The Bacterial Microbiota of Gastrointestinal Cancers: Role in Cancer Pathogenesis and Therapeutic Perspectives

The microbiota has an essential role in the pathogenesis of many gastrointestinal diseases including cancer. This effect is mediated through different mechanisms such as damaging DNA, activation of oncogenic pathways, production of carcinogenic metabolites, stimulation of chronic inflammation, and inhibition of antitumor immunity. Recently, the concept of "pharmacomicrobiomics" has emerged as a new field concerned with exploring the interplay between drugs and microbes. Mounting evidence indicates that the microbiota and their metabolites have a major impact on the pharmacodynamics and therapeutic responses toward anticancer drugs including conventional chemotherapy and molecular-targeted therapeutics. In addition, microbiota appears as an attractive target for cancer prevention and treatment. In this review, we discuss the role of bacterial microbiota in the pathogenesis of different cancer types affecting the gastrointestinal tract system. We also scrutinize the evidence regarding the role of microbiota in anticancer drug responses. Further, we discuss the use of probiotics, fecal microbiota transplantation, and antibiotics, either alone or in combination with anticancer drugs for prevention and treatment of gastrointestinal tract cancers.

Pathogenic B-cell receptor signaling in lymphoid malignancies: New insights to improve treatment

Signals emanating from the B-cell receptor (BCR) promote proliferation and survival in diverse forms of B-cell lymphoma. Precision medicine strategies targeting the BCR pathway have been generally effective in treating lymphoma, but often fail to produce durable responses in diffuse large B-cell lymphoma (DLBCL), a common and aggressive cancer. New insights into DLBCL biology garnered from genomic analyses and functional proteogenomic studies have identified novel modes of BCR signaling in this disease. Herein, we describe the distinct roles of antigen-dependent and antigen-independent BCR signaling in different subtypes of DLBCL. We highlight mechanisms by which the BCR cooperates with TLR9 and mutant isoforms of MYD88 to drive sustained NF-κB activity in the activated B-cell-like (ABC) subtype of DLBCL. Finally, we discuss progress in detecting and targeting oncogenic BCR signaling to improve the survival of patients with lymphoma.

Prognostic significance of helicobacter pylori-infection in gastric diffuse large B-cell lymphoma

Background

Helicobacter pylori (H. pylori) is thought to have an oncogenic effect on the development of gastric malignancies. However, the effect of H. pylori status on the prognosis of gastric diffuse large B-cell lymphoma (DLBCL) remains unconfirmed. This study aimed to identify the prognostic importance of H. pylori infection in de novo gastric DLBCL.

Methods

One hundred and twenty-nine patients diagnosed with primary de novo gastric DLBCL at the West China Hospital of Sichuan University from 1st January 2009 to 31st May 2016 were included. The clinical features of the patients were documented. H. pylori status was assessed via urease breath tests and histologic examinations. The prognostic value of H. pylori was verified via univariate and multivariate analyses.

Results

Over a median follow-up of 52.2 months (range 4–116), the 5-year overall survival (OS) for all patients was 78.7%. Patients with H. pylori infections had significantly better 5-year PFS and OS than did the H. pylori-negative subgroup (5-year PFS, 89.3% vs. 74.1%, P = 0.040; 5-year OS, 89.7% vs. 71.8%, P = 0.033). Negative H. pylori status and poor ECOG performance were independent negative prognostic indicators for both PFS and OS (PFS, P = 0.045 and P = 0.001, respectively; OS, P = 0.021 and P < 0.001, respectively).

Conclusions

H. pylori status in de novo gastric DLBCL can be a promising predictor of disease outcome, and patients with negative H. pylori status require careful follow-up since they tend to have a worse outlook.

Serological Assessment of 18 Pathogens and Risk of AIDS-Associated Non-Hodgkin Lymphoma

BACKGROUND

HIV infection is associated with increased susceptibility to common pathogens, which may trigger chronic antigenic stimulation and hyperactivation of B cells, events known to precede the development of AIDS-associated non-Hodgkin lymphoma (AIDS-NHL).

METHODS

To explore whether cumulative exposure to infectious agents contributes to AIDS-NHL risk, we tested sera from 199 AIDS-NHL patients (pre-NHL, average lead time 3.9 years) and 199 matched HIV-infected controls from the Multicenter AIDS Cohort Study, for anti-IgG responses to 18 pathogens using multiplex serology. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using conditional logistic regression models.

RESULTS

We found no association between cumulative exposure to infectious agents and AIDS-NHL risk (OR 1.01, 95% CI: 0.91 to 1.12). However, seropositivity for trichodysplasia spinulosa polyomavirus (TSPyV), defined as presence of antibodies to TSPyV capsid protein VP1, was significantly associated with a 1.6-fold increase in AIDS-NHL risk (OR 1.62, 95% CI: 1.02 to 2.57). High Epstein-Barr virus (EBV) anti-VCA p18 antibody levels closer to the time of AIDS-NHL diagnosis (<4 years) were associated with a 2.6-fold increase in AIDS-NHL risk (OR 2.59, 95% CI: 1.17 to 5.74). In addition, high EBV anti-EBNA-1 and anti-ZEBRA antibody levels were associated with 2.1-fold (OR 0.47, 95% CI: 0.26 to 0.85) and 1.6-fold (OR 0.57, 95% CI: 0.35 to 0.93) decreased risk of AIDS-NHL, respectively.

CONCLUSIONS

Our results do not support the hypothesis that cumulative exposure to infectious agents contributes to AIDS-NHL development. However, the observed associations with respect to TSPyV seropositivity and EBV antigen antibody levels offer additional insights into the pathogenesis of AIDS-NHL.

Gastric MALT lymphoma and Helicobacter pylori

Marginal zone lymphomas of the MALT type are a type of B-cell neoplasms that involve extranodal tissues and have an indolent clinical behaviour. The stomach is the most common site and most patients are infected by Helicobacter pylori. An increase in the resistance of this bacterium to several antibiotics has been observed in the last years and this fact has determined the review of treatment guidelines. In areas with resistance to clarithromycin greater than 15%, classical triple therapy should be abandoned and quadruple regimens with or without bismuth are currently recommended. Thus, these new guidelines for eradication treatment should be applied to patients with gastric MALT lymphoma associated with H. pylori infection.

Histological transformation from gastric mucosa-associated lymphoid tissue lymphoma to gastric diffuse large B-cell lymphoma

This study evaluated the clinical features, treatment and prognosis in Chinese patients with histological transformation (HT) from gastric mucosa-associated lymphoid tissue lymphoma to gastric diffuse large B-cell lymphoma. We reviewed the medical records of 71 patients diagnosed with HT between 2001 and 2013, retrospectively. Patients had a median age of 56 years. The ratio of sex (male:female) was 1.3:1. The clinical course was often insidious, lacking specific clinical presentation. Macroscopically, the antrum was the most commonly involved site. Thirty-one patients (45%) presented at stage I, and 25 (35%) presented with local (18/71, 25%) or distant (7/71, 10%) nodal involvement. There were also stage IIE (9/71, 12%) and stage IV (6/71, 8%) patients with advanced stages. For all 71 patients, the 5-year progression-free survival (PFS) and overall survival (OS) estimates were 50 and 56%, respectively. There was no statistical difference in 5-year PFS and OS estimates between patients receiving Helicobacter pylori (H. pylori) containing eradication (HPE) (p=0.189) and those receiving non-HPE (p=0.359). Upon the Cox regression model, advanced stages were the only independent prognostic factors associated with shorter PFS, and m-IPI was independently associated with shorter PFS and OS. There was no specific clinical manifestation for patients with HT. HPE is thus a promising therapeutic approach for such patients. Moreover, advanced stages and m-IPI significantly influenced patient outcome.

EZH2 overexpression in primary gastrointestinal diffuse large B-cell lymphoma and its association with the clinicopathological features

Gastrointestinal diffuse large B-cell lymphoma (GI DLBCL) is the most common gastrointestinal lymphoma. Enhancer of zeste homolog 2 (EZH2) has been implicated in the pathogenesis of several cancers. However, EZH2 has not been studied in GI DLBCL. Thus, we investigated EZH2 expression and EZH2 Y641 mutation in 100 GI DLBCL specimens by immunohistochemistry and sequencing. In addition, trimethylated H3K27 (H3K27me3), BCL2, c-MYC, and Ki-67 expression and Helicobacter pylori infection were detected, and BCL2 and c-MYC gene translocation was assessed. EZH2 was overexpressed in 50% of cases. EZH2 overexpression was significantly associated with higher stage (P = .014), higher International Prognostic Index score (P = .003), reduced overall survival rate (P = .030), and H3K27me3 (P = .001) and c-MYC expression (P = .008). We detected EZH2 mutations in 1 of 33 (3.0%) DLBCLs with a germinal center immunophenotype. The frequency of EZH2 Y641 mutation in GI DLBCL was significantly lower than that in patients with DLBCL without gastrointestinal features (P = .022). BCL2 and c-MYC translocation was detected in 6.5% and 5.1% of cases, respectively. BCL2 translocation was detected exclusively in the germinal center B-cell-like subtype. Chronic gastroenteritis was present in all cases, and 36.4% of gastric DLBCL cases had H pylori infection. The data indicate that primary GI DLBCL is closely related with chronic inflammation and has a low frequency of molecular abnormality, and EZH2 overexpression is significantly associated with inferior outcome in patients with primary GI DLBCL; evaluating EZH2 expression has therapeutic implications.

Clinical aspects and therapy of gastrointestinal MALT lymphoma

Extranodal marginal zone B-cell lymphomas of the mucosa associated lymphoid tissue (MALT) arise from lymphoid populations that are induced by chronic inflammation in extranodal sites. Among the MALT lymphomas, gastrointestinal (GIT) MALT lymphoma is the most frequent compared to non-GIT MALT lymphoma arising from other sites. Gastric MALT lymphoma has been the first to be described with the evidence of an etiopathogenetic link provided by the association between Helicobacter pylori-positive gastritis and gastric MALT lymphoma. Indeed, successful eradication of this micro-organism with antibiotics can be followed by a lymphoma regression in most cases. When there is no association with Helicobacter pylori, there is no clear therapeutic consensus. Both radiotherapy and systemic treatments with chemotherapy and anti-CD20 antibodies are efficacious and thus the experience of individual centers and each patient's preferences in terms of adverse effects are important parameters in the decision process.

Expressions of the CagA protein and CagA-signaling molecules predict Helicobacter pylori dependence of early-stage gastric DLBCL

Expression of CagA and CagA-signaling molecules p-SHP2 and p-ERK is associated with HP dependence of gastric DLBCL. CagA is associated with the direct lymphomagenic effect of HP on B cells of HP-dependent gastric DLBCL.

Regression of Gastric Large B-Cell Lymphoma Accompanied by a Florid Lymphoma-like T-Cell Reaction: Immunomodulatory Effect of Ganoderma lucidum (Lingzhi)?

Complete regression of high-grade lymphoma is extremely rare. We report 1 such case that might have been conceivably mediated by Ganoderma lucidum (Lingzhi), an immunomodulatory herbal medicine. A 47-year-old man presented with epigastric pain. Endoscopy revealed a large gastric ulcer, which on biopsy was diagnostic of large B-cell lymphoma. At gastrectomy 11 days later, no evidence was found of large B-cell lymphoma despite thorough sampling. Instead, there was a dense and permeative infiltrate of CD3+ CD8+ cytotoxic small T lymphocytes spanning the whole thickness of the gastric wall. In situ reverse transcription polymerase chain reaction for T-cell receptor β-chain family did not detect a monoclonal T-cell population. We postulate that the cytotoxic T cells may represent an active host−immune response against the large B-cell lymphoma that resulted in a complete regression. On questioning, the patient had taken megadoses of Ganoderma lucidum, which might have triggered the successful immune reaction.

The spectrum of MALT lymphoma at different sites: biological and therapeutic relevance

Extranodal marginal zone (MZ) B-cell lymphomas of the mucosa-associated lymphoid tissue (MALT) arise from lymphoid populations that are induced by chronic inflammation in extranodal sites. The best evidence of an etiopathogenetic link is provided by the association between Helicobacter pylori–positive gastritis and gastric MALT lymphoma. Indeed, successful eradication of this microorganism with antibiotics can be followed by gastric MALT lymphoma regression in most cases. Other microbial agents have been implicated in the pathogenesis of MZ lymphoma arising at different sites. Apart from gastric MALT lymphoma, antibiotic therapies have been adequately tested only in ocular adnexal MALT lymphomas where upfront doxycycline may be a reasonable and effective initial treatment of patients with Chlamydophila psittaci–positive lymphoma before considering more aggressive strategies. In all other instances, antibiotic treatment of nongastric lymphomas remains investigational. Indeed, there is no clear consensus for the treatment of patients with gastric MALT lymphoma requiring further treatment beyond H pylori eradication or with extensive disease. Both radiotherapy and systemic treatments with chemotherapy and anti-CD20 antibodies are efficacious and thus the experience of individual centers and each patient’s preferences in terms of adverse effects are important parameters in the decision process.

Repurposing Drugs in Oncology (ReDO)-clarithromycin as an anti-cancer agent

Clarithromycin (CAM) is a well-known macrolide antibiotic available as a generic drug. CAM is traditionally used for many types of bacterial infections, treatment of Lyme disease and eradication of gastric infection with Helicobacter pylori. Extensive preclinical and clinical data demonstrate a potential role for CAM to treat various tumours in combination with conventional treatment. The mechanisms of action underlying the anti-tumour activity of CAM are multiple and include prolonged reduction of pro-inflammatory cytokines, autophagy inhibition, and anti-angiogenesis. Here, we present an overview of the current preclinical (in vitro and in vivo) and clinical evidence supporting the role of CAM in cancer. Overall these findings justify further research with CAM in many tumour types, with multiple myeloma, lymphoma, chronic myeloid leukaemia (CML), and lung cancer having the highest level of evidence. Finally, a series of proposals are being made to further investigate the use of CAM in clinical trials which offer the greatest prospect of clinical benefit to patients.

Gastric MALT lymphoma - update on diagnosis and treatment

Gastrointestinal lymphoma represent a heterogenous group with differences in pathogenesis, treatment and prognosis. Gastric MALT lymphoma is the most common entity. Helicobacter pylori has been identified as its decisive pathogenetic factor. Once a definitive diagnosis has been established a staging procedure is obligatory for defining the stage of disease. H. pylori eradication is the treatment of choice in all MALT lymphoma patients being infected by the bacterium. In some 70-80% of patients with stages I/II complete regression of the lymphoma will develop after successful eradication of H. pylori. Another 20% of patients will reveal minimal histological residuals after eradication. They can be successfully managed by a watch-and-wait strategy if initial endoscopic abnormalities disappear. At present, it is unclear if this strategy can be also offered to patients with persisting minimal endoscopic abnormalities. Why eradication therapy is effective in some patients with negative H. pylori status is highly speculative at present. Non-responders to H. pylori therapy are transferrred to radiotherapy in stages I/II or to immuno-chemotherapy in stages III/IV.

Application of the BIOMED-2 standardized primer system for the diagnosis of primary gastric B-cell non-Hodgkin's lymphoma

Primary gastric B-cell non-Hodgkin's lymphoma (B-NHL) has a similar morphocytological presentation to severe chronic gastritis, which complicates the pathological diagnosis of this disease. To investigate the practicality and utility of the BIOMED-2 standardized primer system for the diagnosis of primary gastric B-NHL from endoscopic biopsy specimens, we selected 65 cases of archived paraffin-embedded primary gastric B-NHL specimens as well as 27 cases of severe chronic gastritis samples to serve as a negative control group. The positivity rates of immunoglobulin heavy chain (IgH) gene rearrangements detected by the BIOMED-2 standardized primer system for the two groups were 86.4% and 12.0%, respectively, which are significantly different (p < 0.05). Importantly, the combined detection of the five groups of the IgH primer system increased the detection rate of B-NHL. These findings indicate that the BIOMED-2 standardized primer system is suitable for formalin-fixed and paraffin-embedded (FFPE) specimens and is valuable as a secondary diagnostic tool for primary gastric B-NHL as well as the differential diagnosis of severe chronic gastritis.

The role of Helicobacter pylori eradication in the treatment of diffuse large B-cell and marginal zone lymphomas of the stomach

PURPOSE OF REVIEW

This review is focused on the effect of Helicobacter pylori eradication with antibiotics in patients with primary gastric lymphomas of indolent and aggressive nature.

RECENT FINDINGS

Gastrointestinal lymphoma is the most common form of extranodal lymphoma, involving primarily the stomach in 60-75% of cases. The most common histological subtypes are diffuse large B-cell lymphoma (DLBCL) and marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT)-type. H. pylori infection has been implicated in the pathogenesis of gastric MALT lymphoma; its role in gastric DLBCL remains controversial. Recently, international guidelines established that patients with gastric MALT lymphoma should be treated with upfront H. pylori-eradicating antibiotic therapy and that residual microscopic or molecular disease does not need for additional antiblastic treatment. The excellent prognosis of patients with gastric DLBCL managed with conservative chemo-radiotherapy led some investigators to test H. pylori eradication as exclusive treatment in prospective trials, keeping chemo-radiotherapy for unresponsive patients. This conservative strategy was well tolerated and active in patients with limited-stage DLBCL (±MALT areas) of the stomach.

SUMMARY

H. pylori eradication is a suitable strategy as exclusive upfront treatment for both patients with MALT-type lymphomas or with DLBCL of the stomach. Additional trials are needed to elucidate related controversial issues.

Gastric diffuse large B-cell lymphoma cured with Helicobacter pylori eradication regardless of whether it contains features of MALT lymphoma

A 66-year-old patient was diagnosed with primary gastric B-cell lymphoma. The pathological findings were consistent with diffuse large B-cell lymphoma (DLBCL); however, a small area showed features of mucosa-associated lymphoid tissue (MALT) lymphoma. Biopsy specimens were referred to two other pathologists, both of whom diagnosed the case as pure DLBCL, denying the area of MALT lymphoma. As the lymphoma was limited to the submucosal layer and the patient's general condition was excellent, eradication of Helicobacter pylori was selected as the initial treatment. The lymphoma completely disappeared three months after the eradication treatment, and complete remission has been maintained for nearly two years.

Helicobacter pylori and mucosa-associated lymphoid tissue: what's new

Low-grade mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach, gastric MALT lymphoma, is associated with Helicobacter pylori infection. The eradication of H pylori using antibiotics is successful in 60% to 80% of affected patients. In contrast to the previous paradigm, we and other investigators have shown that a certain proportion of patients with H pylori-positive early-stage diffuse large B-cell lymphoma (DLBCL) of the stomach with histological evidence of MALT lymphoma, including high-grade transformed gastric MALT lymphoma and gastric DLBCL(MALT), achieved long-term complete pathological remission (pCR) after first-line H pylori eradication therapy, indicating that the loss of H pylori dependence and high-grade transformation are separate events in the progression of gastric lymphoma. In addition, patients with H pylori-positive gastric DLBCL without histological evidence of MALT (gastric pure DLBCL) may also respond to H pylori eradication therapy. A long-term follow-up study showed that patients who achieved pCR remained lymphoma free. Gastric MALT lymphoma is indirectly influenced by H pylori infection through T-cell stimulation, and recent studies have shown that H pylori-triggering chemokines and their receptors, H pylori-associated epigenetic changes, H pylori-regulated miRNA expression, and tumor infiltration by CD4+CD25+ regulatory T cells contribute to lymphomagenesis of gastric MALT lymphoma. Recent studies have also demonstrated that the translocation of CagA into B lymphocytes inhibits apoptosis through p53 accumulation, BAD phosphorylation, and the up-regulation of Bcl-2 and Bcl-XL expression. In gastric MALT lymphoma, CagA may stimulate lymphomagenesis directly, through the regulation of signal transduction, and intracellular CagA is associated with H pylori dependence. These findings represent a substantial paradigm shift compared with the classical theory of H pylori-reactive T cells contributing indirectly to the development of MALT lymphoma. In conclusion, a wide range of H pylori-related gastric lymphomas have been identified. The use of antibiotics as the sole first-line therapy for early-stage gastric pure DLBCL requires validation in a prospective study. The clinical and biological significance of the CagA oncoprotein in the lymphomagenesis of gastric MALT lymphoma warrants further study.

Helicobacter pylori eradication therapy is effective in the treatment of early-stage H pylori-positive gastric diffuse large B-cell lymphomas

An explorative study evaluates the efficacy of Helicobacter pylori (HP) eradication (HPE) therapy on early-stage gastric diffuse large B-cell lymphomas (DLBCLs) without features of mucosa-associated lymphoid tissue (MALT), the pure (de novo) DLBCLs, in comparison with its efficacy on high-grade transformed gastric MALT lymphomas, the DLBCL(MALT). In total, 50 patients of stage IE/IIE1 HP-positive gastric DLBCLs with frontline HPE treatment were included. HP infection was successfully eradicated in 100% (16/16) of the pure (de novo) DLBCL patients and 94.1% (32/34) of the DLBCL(MALT) patients. In total, 68.8% (11/16) of pure (de novo) DLBCL patients and 56.3% (18/32) of DLBCL(MALT) patients achieved complete pathologic remission (pCR) after HPE therapy. The median time to pCR was 2.1 months (95% confidence interval, 0.6%-3.7%) for pure (de novo) DLBCLs and 5.0 months (95% confidence interval, 2.8%-7.5%; P = .024) for DLBCL(MALT). At a median follow-up of 7.7 years, all patients with pCR after HPE therapy were alive and free of lymphomas, except for one patient with pure (de novo) DLBCL who died of lung cancer. Similar to DLBCL(MALT), a substantial portion of early-stage HP-positive gastric pure (de novo) DLBCLs remains HP-dependent and responds to antibiotic treatment. Prospective studies to validate the findings are warranted.

Review article: common misconceptions in the management of Helicobacter pylori-associated gastric MALT-lymphoma

BACKGROUND

Helicobacter pylori infection is the main cause of gastric mucosa-associated lymphoid tissue (MALT) lymphoma.

AIM

To review several common misconceptions in the management of H. pylori-associated gastric MALT-lymphoma.

METHODS

Bibliographical searches were performed in MEDLINE up to June 2011.

RESULTS

If adequate diagnostic methods are used, and if only low-grade lymphomas are considered, the prevalence of H. pylori infection is very high (almost 90%). H. pylori eradication is effective in treating approximately 80% of patients with early stage lymphoma. In H. pylori-positive gastric high-grade lymphomas, antibiotic therapy should always be prescribed, as approximately 50% of them regress after H. pylori eradication. Patients with early stage MALT lymphoma negative for H. pylori might still benefit from antibiotic treatment as the sole treatment. Complete remission of gastric MALT lymphoma after H. pylori eradication can take even >12 months. PCR assay for the detection of monoclonal B cells remains positive in many cases after complete remission has been reached. Patients with a persistent clonal band should not be treated unless the lymphoma can be histologically demonstrated. Synchronous occurrence of gastric adenocarcinoma and MALT lymphoma has been repeatedly reported. In some patients in complete remission, eradication of H. pylori does not prevent later development of early gastric cancer. Gastric lymphoma recurrence occurs in some patients after both bacterial and lymphoma regression. H. pylori reinfection does not constitute a prerequisite for lymphoma recurrence.

CONCLUSIONS

The present article states several misconceptions in the management of H. pylori-associated gastric MALT-lymphoma in clinical practice, reviews the related scientific evidence and proposes the adequate attitude in each case.

Lymphosarcoma associated with Heterobilharzia americana infection in a dog

Hepatic T-cell lymphosarcoma with involvement of regional lymph nodes and concurrent schistosomiasis were diagnosed in an 11-year-old male neutered mixed-breed dog with a history of chronic weight loss, inappetence, vomiting, and diarrhea. Trematode ova present in the hepatic parenchyma and mesenteric node were surrounded by sheets of neoplastic lymphocytes while those in the intestinal wall were surrounded by large numbers of non-neoplastic lymphocytes. Immunohistochemistry revealed that both the neoplastic and hyperplastic populations were T lymphocytes. The ova were identified by fecal saline sedimentation as Heterobilharzia spp., and fecal ova shedding resolved after praziquantel anthelmintic treatment. The lymphoma progressed despite chemotherapy, and the dog was euthanized after developing neurologic signs and a necropsy was performed. A monomorphic population of neoplastic T cells expanded and replaced normal architecture in the liver and spleen, surrounded nerve roots within the cauda equina, and infiltrated the meninges of the brain. The presence of schistosome ova embedded within neoplastic T-cell infiltrates suggests that, as previously reported in human schistosomiasis, heterobilharziasis may be associated with neoplasia.

Infectious agents and lymphoma

In the past 25 years revelations on the genesis of human cancer have come at an increasing pace. Research on oncogenic infectious agents, especially viruses, has helped us to understand the process of malignant transformation of cells because the cellular events in viral-driven transformation mirror, often brilliantly, basic cellular processes that culminate in cancer, even those not associated with viruses. Infectious agents, especially viruses, account for several of the most common malignancies-up to 20% of all cancers. Some of these cancers are endemic, with a high incidence in certain geographic locations, but sporadic/lower incidence in other parts of the world. Lymphomas arise frequently in association with infectious agents such as Epstein-Barr virus, human immunodeficiency virus, human herpes virus 8, Helicobacter pylori, and hepatitis C virus. In this review, we will focus on the association between infectious agents and lymphomas, with a look at the molecular mechanisms they use to disturb cell regulation and eventually result in cancer.

Polymorphisms in the 3'-untranslated region of the CDH1 gene are a risk factor for primary gastric diffuse large B-cell lymphoma

BACKGROUND

Primary gastric B-cell lymphomas arise from mucosa-associated lymphatic tissue (MALT) in patients with chronic Helicobacter pylori infection. We investigated whether germline variants in the CDH1 gene, coding for E-cadherin, genetically predispose patients to primary gastric B-cell lymphoma.

DESIGN AND METHODS

Single marker analyses of the CDH1 gene were conducted in patients with primary gastric B-cell lymphoma (n=144), in patients with primary gastric high-grade lymphoma (n=61), and in healthy blood donors (n=361). Twelve single nucleotide polymorphisms were genotyped by TaqMan(®) technology. Allelic imbalance was tested by pyrosequencing and clone direct sequencing of heterozygote genomic and cDNA. Mutation detection was conducted around the poly-A signal of the CDH1 3'-untranslated region. The influence of the 3'-untranslated region on protein translation was determined by a luciferase reporter assay.

RESULTS

Single marker analyses identified two single nucleotide polymorphisms in strong linkage disequilibrium located in the CDH1 3'-untranslated region. One of them was significantly associated with primary gastric diffuse large B-cell lymphomas after correction for multiple testing and this association was confirmed in an independent sample set. Patients homozygous for the rare T allele (rs1801026) had a 4.9-fold increased risk (95% CI: 1.5-15.9) of developing primary gastric diffuse large B-cell lymphoma. Allelic imbalance and reporter gene assays indicated a putative influence on mRNA stability and/or translational efficacy.

CONCLUSIONS

We identified variants in CDH1 as the first potential genetic risk factors for the development of primary gastric diffuse large B-cell lymphomas. One of the potentially causative variants affects allelic CDH1 expression. These findings support the hypothesis that besides somatic alterations of B-cells, germline variants in the CDH1 gene contribute to a predisposition to the development of primary gastric diffuse large B-cell lymphomas.

Primary low-grade and high-grade gastric MALT-lymphoma presentation

GOAL

To assess the clinical and endoscopic presentation of primary gastric lymphoma.

BACKGROUND

Remission rate and long-term survival in patients with gastric lymphoma mainly depend on disease stage at diagnosis. Series reporting clinical and endoscopic presentation of gastric lymphoma are generally small and heterogeneous.

STUDY

Systematic review with pooled-data analysis assessing clinical and endoscopic presentation of primary gastric lymphoma.

RESULTS

Data regarding 2000 patients were collected. Overall, males were slightly more prevalent, alarm symptoms were absent in near half of the patients, lymphoma was diagnosed in a stage >I in one-third of the patients, and Helicobacter pylori infection was present in 88.8% of considered patients. At endoscopy, the ulcerative type was the most frequent presentation, although low-grade lymphoma was diagnosed on normal/hyperemic gastric mucosa in 9% of cases. Patients with high-grade lymphoma presented alarm symptoms (anemia and/or melena and/or hemorrhage, persistent vomiting, weight loss), an exophytic or ulcerative lesion, a stage III-IV, and a H. pylori negative status more frequently than low-grade lymphoma cases.

CONCLUSIONS

Our pooled-data analysis showed that gastric lymphoma is still disappointingly diagnosed in an advanced stage in a large number of patients. This is probably due to presence of nonspecific symptoms at initial clinical presentation and/or a normal appearing mucosa at endoscopic observation in the early stages.

Long-term follow-up of gastric lymphoma after stomach conserving treatment

The therapeutic strategy in gastric lymphoma has completely changed over the last two decades. This change is mainly characterised by the abandonment of surgery in favour of conservative therapies and the introduction of Helicobacter pylori eradication therapy. It became evident that conservative treatment with radiation and/or chemotherapy is at least as effective as surgical resection and additionally offers the advantage of stomach preservation and better quality of life. The therapeutic goal is undoubtedly complete remission of the lymphoma as a necessary basis for cure of the disease. Both radiotherapy and chemotherapy have a high curative potential in gastric MALT lymphoma and diffuse large B-cell lymphoma (DLBCL), respectively. An open question is the additional benefit of radiation following Rituximab-CHOP chemotherapy in DLBCL. In patients with gastric MALT lymphoma of stage I H. pylori eradication offers complete remission rates of up to 80% with excellent long-term prognosis and a real chance of cure. Patients with MALT lymphoma of stage II and those with DLBCL of stage I may also respond to eradication therapy in the individual case. It also emerged recently that there is no need for any oncological therapy in patients revealing minimal histological residuals after successful H. pylori eradication. A watch-and-wait strategy is the adequate management of this condition. In summary, therapy of gastric lymphoma is nowadays individualised with lymphoma type, stage, and H. pylori status as the determinants of the choice of treatment. Efficacy and quality of life are strong arguments for a definite conservative approach encompassing H. pylori eradication, radiation and chemotherapy.

Pulmonary lymphoma mimicking metastases: a case report

Introduction

Lung mass is a common radiological finding among elderly. Bronchogenic carcinoma with metastases is the commonest cause of lung mass with multiple nodules in same or other lung seen in this age group. However, sometimes other uncommon malignancies with better prognosis can also present similarly. Primary pulmonary lymphoma is one of the rare malignancies, which have similar radiological presentation but different treatment and prognosis.

Case presentation

We present a non-smoking, elderly, diabetic man who presented with nonspecific symptoms of generalized weakness without any symptom pertaining to respiratory system. Examination of chest revealed findings suggestive of right lower lobe mass. On evaluation, he was found to have a well circumscribed lung mass on chest radiograph. Computerized tomography of chest with contrast showed a large mass involving right lung and multiple nodules in both lungs. For diagnosis, biopsy from right lung mass was done under image guidance. Histopathology revealed diffuse large B-cell non-Hodgkins lymphoma. Evaluation for primary malignancy leading to lung metastases was inconclusive. Patient was advised chemotherapy.

Conclusion

Primary pulmonary lymphoma is a rare disease and can present with non specific symptoms. Radiologically, it can easily be confused with commoner malignancies like, bronchogenic carcinoma with or without metastases. Primary pulmonary lymphoma carries different therapeutic and prognostic implications. Therefore, physicians should make every effort to achieve histopathological diagnosis before prognosticating patient presenting with lung mass.

Predictive value of endoscopy and endoscopic ultrasonography for regression of gastric diffuse large B-cell lymphomas after Helicobacter pylori eradication

BACKGROUND

Some gastric diffuse large B-cell lymphomas have been reported to regress completely after the successful eradication of Helicobacter pylori. The aim of this study was to investigate the clinical characteristics of gastric diffuse large B-cell lymphomas without any detectable mucosa-associated lymphoid tissue (MALT) lymphoma that went into complete remission after successful H. pylori eradication.

PATIENTS AND METHODS

We examined the effect of H. pylori eradication in 15 H. pylori-positive gastric diffuse large B-cell lymphoma patients without any evidence of an associated MALT lymphoma (clinical stage I by the Lugano classification) by endoscopic examination including biopsies, endoscopic ultrasonography, computed tomography, and bone marrow aspiration.

RESULTS

H. pylori eradication was successful in all the patients and complete remission was achieved in four patients whose clinical stage was I. By endoscopic examination, these gastric lesions appeared to be superficial. The depth by endoscopic ultrasonography was restricted to the mucosa in two patients and to the shallow portion of the submucosa in the other two patients. All four patients remained in complete remission for 7-100 months.

CONCLUSION

In gastric diffuse large B-cell lymphomas without a concomitant MALT lymphoma but associated with H. pylori infection, only superficial cases and lesions limited to the shallow portion of the submucosa regressed completely after successful H. pylori eradication. The endoscopic appearance and the rating of the depth of invasion by endosonography are both valuable for predicting the efficacy of H. pylori eradication in treating gastric diffuse large B-cell lymphomas.

Eradication therapy for Helicobacter pylori in patients with gastric MALT lymphoma: a pooled data analysis

OBJECTIVES

Helicobacter pylori eradication is recognized as the initial therapy for gastric low-grade, B-cell, mucosa-associated lymphoid tissue (MALT) lymphoma. This study assesses (i) the H. pylori eradication rates for various first- and second-line and rescue therapies and (ii) the associated reinfection rates in patients.

METHODS

Pooled data analysis of systematic review of the literature was performed in this study.

RESULTS

Data from 34 studies with 1,271 treated patients were used. After first-line therapy, the infection was cured in 91% (95% confidence interval (CI)=89.4-92.5) of cases, the eradication rate being higher after dual therapy compared with the 7- or 14-day triple therapies (P=0.0525). After second-line therapy, the eradication rate was 80.8% (95% CI=82.7-95.1), being higher after triple rather than quadruple therapy. Further therapies (from three to five attempts) cured the infection in 75% of patients. H. pylori infection was ultimately cured in 1,250 patients, resulting in eradication rates of 98.3% (95% CI=97.6-99) and 99.8% (95% CI=99.6-100) at intention-to-treat and per-protocol analysis levels, respectively. Bacterial reinfection occurred in 18 (2.7%; 95% CI=1.4-3.9) of 676 patients who were followed-up (0.7% yearly). Overall, gastric lymphoma remission was achieved in 973 (77.8%) of 1,250 patients successfully cured of H. pylori infection.

CONCLUSIONS

This was the first comprehensive ( approximately 1,300 patients) analysis of the therapeutic management of H. pylori in gastric lymphoma patients. Data suggest that this infection is easily managed in these patients, being cured in nearly all cases.

[The value of radiotherapy in the treatment of aggressive and localised gastric lymphomas]

PURPOSE

To evaluate the treatment results of localised aggressive gastric lymphomas with favourable prognosis using chemotherapy and radiotherapy.

PATIENTS AND METHODS

Between February 1993 and December 2004, nine patients with primary gastric high-grade lymphoma have been treated by the Lymphoma Committee of Sfax (Tunisia). The sex ratio was 1.5. The mean age was 44.9 years. Histological type was the large cell B lymphoma in 100% of the cases. Disease was stage I in eight cases and stage II in one case (Ann Arbor Classification). The treatment consisted in primary chemotherapy followed by radiotherapy of the stomach with or without regional nodes (40 Gy).

RESULTS

After treatment, all patients had complete remission. With a mean follow-up of 55.7 months, one patient was lost to follow-up; the other patients were alive with complete remission. No major acute toxicities or late effects were found. Overall survival was 100% at five years.

CONCLUSION

Chemotherapy associated with radiotherapy can be proposed to patients having localised and aggressive primary gastric lymphoma with favourable prognosis, since this treatment is well tolerated and provides satisfactory control of the disease.

Presence of a high-grade component in gastric mucosa-associated lymphoid tissue (MALT) lymphoma is not associated with an adverse prognosis

Gastric mucosa-associated lymphoid tissue (MALT) lymphoma and diffuse large B cell lymphoma (DLBCL) show a spectrum of disease characterized by varying proportions of low-grade and high-grade components. While the natural history and optimum treatment for low-grade gastric MALT lymphoma and DLBCL is well established, the prognosis and optimal treatment of patients with both low- and high-grade components is not well established. The purpose of our study was to evaluate the clinical characteristics, survival outcomes, and prognostic factors of patients with gastric MALT lymphoma and gastric DLBCL. A retrospective review of patients with gastric MALT lymphoma, gastric DLBCL, or MALT lymphoma with a high-grade component treated at our centers from 1994 to 2006 was performed. Patients were divided into three categories: "pure MALT lymphoma," "MALT lymphoma with high-grade component" (mixed), and "pure DLBCL." Seventy-six patients were included in our study-26 with pure MALT, 22 with MALT with high-grade component ("mixed"), and 28 with pure DLBCL. Pure MALT lymphoma and mixed lymphoma patients had similar clinical characteristics, whereas pure DLBCL patients had less favorable disease characteristics with significantly poorer performance status, higher number of extranodal sites of disease, higher stage, and larger proportion of bone marrow involvement and international prognostic index (IPI) scores compared with mixed lymphoma. The majority of mixed lymphoma (72.7%) and DLBCL patients (71.4%) were treated with chemotherapy. Of patients receiving chemotherapy, a higher proportion of mixed lymphoma and DLBCL patients received anthracycline-based combination chemotherapy regimens compared with MALT lymphoma (73% vs 71% vs 8%) whereas the proportion of mixed lymphoma and DLBCL patients was similar (p = 0.919). At a median follow-up of 37 months, the 5-year overall survival was 66.9%. The 5-year overall survival was 78% for MALT lymphoma, 84% for mixed lymphoma, and 45% for DLBCL. On univariate analysis, DLBCL histology, age, performance status, serum albumin, lactate dehydrogenase, bone marrow, number of extranodal sites, stage, and IPI score were prognostic for inferior survival. On multivariate analysis, DLBCL histology remained significantly prognostic for inferior survival, independent of chemotherapy regimen (hazard ratio (HR) 6.66, 95% confidence interval (CI) 2.01-21.41, p = 0.001). Mixed histology was not prognostic for inferior survival (HR 1.13, 95% CI 0.28-4.54, p = 0.868). Other factors prognostic for inferior survival were serum albumin <37 g/L (HR 3.22, 95% CI 1.11-13.22, p = 0.034) and treatment with non-cyclophosphamide, doxorubicin, vincristine, and prednisolone chemotherapy (HR 4.89, 95% CI 1.67-14.36, p = 0.004). In conclusion, the clinical characteristics of mixed histology MALT lymphoma are similar to low-grade MALT lymphoma and significantly different from pure DLBCL. The prognosis of mixed histology MALT lymphoma is significantly better than pure DLBCL, independent of IPI and chemotherapy regimen, and pure DLBCL histology is independently prognostic of inferior survival outcome.

Significance of CXCR3 expression in gastric low-grade B-cell lymphoma of mucosa-associated lymphoid tissue type for predicting responsiveness to Helicobacter pylori eradication

Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is a distinct low-grade lymphoma that often regresses upon Helicobacter pylori eradication. It was reported that the chemokine receptor CXCR3 is expressed not only on activated T cells, but also on MALT lymphoma cells, and that CXCR3-positive B lymphocytes migrate or home to the MALT of MALT lymphoma. In the present study, we aimed to elucidate the correlation between CXCR3 expression and the clinicopathological features of gastric MALT lymphoma, and to determine whether CXCR3 expression was predictive of responsiveness to H. pylori eradication. Sixty-seven patients with gastric MALT lymphoma in a single-center study were treated with H. pylori eradication therapy. We evaluated the correlation of CXCR3 expression with response to H. pylori eradication therapy by logistic regression stratified according to potential confounders. Immunohistochemical analysis revealed that 28 of 67 cases (42%) were positive for CXCR3 expression. CXCR3 expression was significantly more prevalent in those without H. pylori infection, advanced-stage disease, and in those with API2-MALT1 fusion. In overall analysis, those with CXCR3 expression showed a significantly increased risk of non-responsiveness to H. pylori eradication therapy (odds ratio = 28.6; 95% confidence interval 5.70-143.4) compared to those without CXCR3 expression. This higher risk was observed consistently regardless of sex, API2-MALT1 fusion, H. pylori infection, or clinical stage. We showed that CXCR3 expression was an independent predictive factor for non-responsiveness to H. pylori eradication therapy in patients with gastric MALT lymphoma.

Primary extranodal lymphomas of stomach: clinical presentation, diagnostic pitfalls and management

Gastrointestinal lymphoma is the most common form of extranodal lymphoma, accounting for 30%-40% of cases. The most commonly involved site is the stomach (60%-75% of cases), followed by the small bowel, ileum, cecum, colon and rectum. The most common histological subtypes are diffuse large B-cell lymphoma (DLBCL) and marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT). Helicobacter pylori infection has been implicated in the pathogenesis of MALT gastric lymphoma, but its role in gastric diffuse large B-cell non-Hodgkin's lymphoma (NHL) is controversial. The therapeutic approach for patients with gastric NHL has been revised over the last 10 years. Conservative treatment with anthracycline-based chemotherapy alone or in combination with involved-field radiotherapy has replaced gastrectomy as standard therapy in cases with DLBCL. Additionally, MALT lymphomas are mainly treated with antibiotics alone, which can induce lasting remissions in those cases associated with H. pylori infection. Nevertheless, various therapeutic aspects for primary gastric lymphomas are still controversial and several questions remain unanswered. Among others, the role of rituximab, consolidation radiotherapy as well as H. pylori eradication in histological aggressive subtypes warrants better clarification.

High grade B-cell gastric lymphoma with complete pathologic remission after eradication of Helicobacter pylori infection: report of a case and review of the literature

Background

Treatment of primary gastric diffuse large B-cell lymphoma is still controversial. The treatment of localized disease was based on surgery alone, or followed by chemotherapy and/or radiotherapy. High-grade gastric lymphomas are generally believed to be Helicobacter pylori (HP)-independent growing tumors. However a few cases of regression of high-grade gastric lymphomas after the cure of Helicobacter pylori infection had been described.

Case presentation

We report here a case with primary diffuse large B-cell lymphoma that showed a complete pathologic remission after HP eradication and we reviewed the literature. A computerized literature reach through Medline, Cancerlit and Embase were performed, applying the words: high grade gastric lymphoma, or diffuse large B cell, MALT gastric lymphoma, DLBCLL (MALT) lymphoma and Helicobacter. Articles and abstracts were also identified by back-referencing from original and relevant papers. Selected for the present review were papers published in English before January 2007.

Conclusion

Forty two cases of primary high grade gastric lymphoma that regressed with anti HP treatment were found. There were anedoctal cases reported and patients belonging to prospective studies; four trials studied the effect of eradication of Helicobacter pylori as first line therapy in high grade gastric lymphoma: 22 of a total of 38 enrolled patients obtained complete remission. Depth of gastric wall infiltration and clinical stage were important factors to predict the response to antibiotic therapy. Our case and the review of the literature show that high-grade transformation is not necessarily associated with the loss HP dependence. In early stage, for high-grade B-cell HP-positive gastric lymphomas, given the limited toxicity of anti-HP therapy, this treatment may be considered as one of the first line treatment options.

Therapy of gastric mucosa associated lymphoid tissue lymphoma

Gastric mucosa associated lymphoid tissue (MALT) lymphoma has recently been incorporated into the World Health Organization (WHO) lymphoma classification, termed as extranodal marginal zone B-cell lymphoma of MALT-type. In about 90% of cases this lymphoma is associated with H pylori infection which has been clearly shown to play a causative role in lymphomagenesis. Although much knowledge has been gained in defining the clinical features, natural history, pathology, and molecular genetics of the disease in the last decade, the optimal treatment approach for gastric MALT lymphomas, especially locally advanced cases, is still evolving. In this review we focus on data for the therapeutic, stage dependent management of gastric MALT lymphoma. Hence, the role of eradication therapy, surgery, chemotherapy and radiotherapy is critically analyzed. Based on these data, we suggest a therapeutic algorithm that might help to better stratify patients for optimal treatment success.

A multicenter phase II study of local radiation therapy for stage IEA mucosa-associated lymphoid tissue lymphomas: a preliminary report from the Japan Radiation Oncology Group (JAROG)

PURPOSE

The aim of this study was to evaluate the efficacy and toxicity of moderate dose radiation therapy (RT) for mucosa-associated lymphoid tissue (MALT) lymphoma in a prospective multicenter phase II trial.

METHODS AND MATERIALS

The subjects in this study were 37 patients with MALT lymphoma between April 2002 and November 2004. There were 16 male and 21 female patients, ranging in age from 24 to 82 years, with a median of 56 years. The primary tumor originated in the orbit in 24 patients, in the thyroid and salivary gland in 4 patients each, and 5 in the others. The median tumor dose was 30.6 Gy (range, 30.6-39.6 Gy), depending on the primary site and maximal tumor diameter. The median follow-up was 37.3 months.

RESULTS

Complete remission (CR) or CR/unconfirmed was achieved in 34 patients (92%). The 3-year overall survival, progression-free survival, and local control probability were 100%, 91.9%, and 97.3%, respectively. Thirteen patients experienced Grade 1 acute toxicities including dermatitis, mucositis, and conjunctivitis. One patient developed Grade 2 taste loss. Regarding late toxicities, Grade 2 reactions including hypothyroidism, and radiation pneumonitis were observed in three patients, and Grade 3 cataract was seen in three patients.

CONCLUSIONS

This prospective phase II study demonstrated that moderate dose RT was highly effective in achieving local control with acceptable morbidity in 37 patients with MALT lymphoma.

[Malt lung lymphoma]

MALT lung lymphoma is a low-grade primarily B-cell lymphoma. Most cases develop in a pain free patient presenting a chronic alveolar opacity. In this review, we describe the clinical radiological and pathological features as well as the diagnostic approach to this pathological entity. Prognosis is excellent. Therapeutic options are discussed.

Primary diffuse large B-cell lymphoma of the stomach

The stomach is the extranodal site most commonly involved by non-Hodgkin lymphomas. Diffuse large B-cell lymphoma is the most common histotype category arising in this organ. This is an aggressive lymphoma usually presenting as limited disease, being associated or not to Helicobacter pylori infection and mucosa-associated lymphoid tissue-type areas. Histopathological characteristics are similar to those reported for other diffuse large B-cell lymphomas. It occurs more frequently in males with a median age ranging between 50 and 60 years. With an adequate therapeutic strategy, its prognosis is good, with a 5-year overall survival near to 90%. Conservative treatment with anthracycline-containing chemotherapy, followed or not by involved-field radiotherapy has replaced gastrectomy as standard approach against this malignancy. Several questions on the best treatment remain unanswered. Among others, the role of rituximab, consolidation radiotherapy as well as of more conservative approaches like H. pylori-eradicating antibiotic therapy should be better defined.

Primary gastrointestinal tract lymphoma: diagnosis and management of common neoplasms

Primary gastrointestinal lymphoma represents the most common location of extranodal lymphoma. With the bulk of disease manifesting within the gastrointestinal tract and contiguous lymph nodes, many of the lymphomas occurring in the peripheral lymph nodes can also present with primary gastrointestinal tract involvement. Molecular biology has recently enabled significant progress in the diagnosis and management of primary gastrointestinal lymphoma. Herein, we will discuss the major lymphomas affecting the bowel and highlight their key morphological, immunophenotypical and molecular diagnostic attributes. Similarly, in keeping with recent therapeutic advances, we will briefly discuss some important treatment considerations. Thus, this review is intended to offer clinicians and pathologists an overview of primary gastrointestinal lymphomas.