Gastric MALT lymphoma: from concept to cure

Display of porcine epidemic diarrhea virus spike protein B-cell linear epitope on Lactobacillus mucosae G01 S-layer surface induce a robust immunogenicity in mice

The Porcine epidemic diarrhea virus (PEDV) presents a substantial risk to the domestic pig industry, resulting in extensive and fatal viral diarrhea among piglets. Recognizing the mucosal stimulation triggered by PEDV and harnessing the regulatory impact of lactobacilli on intestinal function, we have developed a lactobacillus-based vaccine that is carefully designed to elicit a strong mucosal immune response. Through bioinformatics analysis, we examined PEDV S proteins to identify B-cell linear epitopes that meet the criteria of being non-toxic, soluble, antigenic, and capable of neutralizing the virus. In this study, a genetically modified strain of Lactobacillus mucosae G01 (L.mucosae G01) was created by utilizing the S layer protein (SLP) as a scaffold for surface presentation. Chimeric immunodominant epitopes with neutralizing activity were incorporated at various sites on SLP. The successful expression of SLP chimeric immunodominant epitope 1 on the surface of L.mucosae G01 was confirmed through indirect immunofluorescence and transmission electron microscopy, revealing the formation of a transparent membrane. The findings demonstrate that the oral administration of L.mucosae G01, which expresses the SLP chimeric immunodominant gene epitope1, induces the production of secreted IgA in the intestine and feces of mice. Additionally, there is an elevation in IgG levels in the serum. Moreover, the levels of cytokines IL-2, IL-4, IFN-γ, and IL-17 are significantly increased compared to the negative control group. These results suggest that L. mucosae G01 has the ability to deliver exogenous antigens and elicit a specific mucosal immune response against PEDV. This investigation presents new possibilities for immunoprophylaxis against PEDV-induced diarrhea.

Changes in Incidence and Survival by Decade of Patients With Primary Colorectal Lymphoma: A SEER Analysis

Purpose: To reveal changes in the incidence, treatment, and survival of patients with colorectal lymphoma. Methods: Patients diagnosed with primary colorectal lymphoma (PCL) or lymphoma between 1973 and 2014 were identified in the SEER registry. The incidence was estimated by age and join-point analysis. The incidence of different subtypes and the surgical resection rates were compared over different time periods. Results: The PCL incidence increased from 1.4 per 1 000 000 people in 1973 to 3.5 in 2014, with an annual percentage change (APC) of 1.98% (95% confidence interval [CI]: 1.29-2.68%, P < 0.001) from 1985 to 2014. No statistically significant change was found between 1973 and 1984. For people younger than 60 years, there was a slight increase in PCL incidence, from 0.6 to 1.4%, from 1973 to 2014. For people age 60 or older, there was a statistically significant increase in PCL incidence from 5.4 to 14.1% over the same time period. The 5-year cause-specific survival (CSS) for PCL improved markedly from 41.6% in the period 1973-1976 to 80.2% in the period 2009-2012 (P < 0.001). Conversely, the proportion of patients who received surgical therapy decreased gradually from 83.3-100 to 47.7-52.6% throughout the studied time period. Conclusions: The incidence of PLC has increased in recent decades. The 5-year CSS of PCL increased continuously, while the rate of surgical resection decreased steadily. These changes in survival trends and therapy strategies indicate that PCL can be well-managed with newer therapeutic reagents.

Radiation therapy for gastric mucosa-associated lymphoid tissue lymphoma: dose-volumetric analysis and its clinical implications

Purpose

To assess the clinical outcomes of radiotherapy (RT) using two-dimensional (2D) and three-dimensional conformal RT (3D-CRT) for patients with gastric mucosa-associated lymphoid tissue (MALT) lymphoma to evaluate the effectiveness of involved field RT with moderate-dose and to evaluate the benefit of 3D-CRT comparing with 2D-RT.

Materials and Methods

Between July 2003 and March 2015, 33 patients with stage IE and IIE gastric MALT lymphoma received RT were analyzed. Of 33 patients, 17 patients (51.5%) were Helicobacter pylori (HP) negative and 16 patients (48.5%) were HP positive but refractory to HP eradication (HPE). The 2D-RT (n = 14) and 3D-CRT (n = 19) were performed and total dose was 30.6 Gy/17 fractions. Of 11 patients who RT planning data were available, dose-volumetric parameters between 2D-RT and 3D-CRT plans was compared.

Results

All patients reached complete remission (CR) eventually and median time to CR was 3 months (range, 1 to 15 months). No local relapse occurred and one patient died with second primary malignancy. Tumor response, survival, and toxicity were not significantly different between 2D-RT and 3D-CRT (p > 0.05, each). In analysis for dose-volumetric parameters, D_max and CI for PTV were significantly lower in 3D-CRT plans than 2D-RT plans (p < 0.05, each) and D_mean and V₁₅ for right kidney and D_mean for left kidney were significantly lower in 3D-CRT than 2D-RT (p < 0.05, each).

Conclusion

Our data suggested that involved field RT with moderate-dose for gastric MALT lymphoma could be promising and 3D-CRT could be considered to improve the target coverage and reduce radiation dose to the both kidneys.

Correlation of Endoscopic Findings of Gastric Mucosa-Associated Lymphoid Tissue Lymphoma with Recurrence after Complete Remission

Background/Aims

In gastric mucosa-associated lymphoid tissue (MALT) lymphoma, the clinical significance of various endoscopic findings has not yet been determined. This study aimed to compare the time to complete remission (CR) and relapse-free survival (RFS) in gastric MALT lymphoma based on endoscopic findings.

Methods

In this single-center retrospective cohort study, the medical records of 122 consecutive adult patients with gastric MALT lymphoma were collected over a period of 12 years. CR was defined by the absence of macroscopic or microscopic features of lymphoma on two subsequent follow-ups. Relapse was clinically defined by a positive endoscopic biopsy after CR.

Results

The median time to CR did not differ significantly between treatment methods. However, it was significantly longer in the group with polypoid endoscopic appearance than in the groups with diffuse infiltration or ulceration (7.83, 3.43, and 3.10 months, respectively; p=0.003). Six patients relapsed after CR. Kaplan-Meier analysis showed that RFS differed significantly between groups based on Ann Arbor staging, treatment methods, and initial endoscopic findings.

Conclusions

In gastric MALT lymphoma, the endoscopically defined polypoid type was characterized by a longer duration to CR, with a higher likelihood of recurrence, compared to the endoscopically defined diffuse infiltration or ulceration types.

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.

Regression of Cecal MALT Lymphoma after Antibiotic Treatment in a Patient with Helicobacter pylori Infection

A 63-year-old man with abdominal discomfort was referred to our hospital. Colonoscopy revealed a hemispherical-shaped protruding cecal mass of approximately 10 mm in size with a normal mucosal surface. Biopsy specimens showed nodules consisting of the proliferation of atypical lymphoid cells. Mucosa-associated lymphoid tissue (MALT) lymphoma was diagnosed based on the histological and immunohistochemical findings. Since upper gastrointestinal endoscopy demonstrated Helicobacter pylori-associated atrophic gastritis, eradication therapy was administered. The cecal mass disappeared completely within three months after triple therapy. Therefore, H. pylori eradication therapy may be a useful treatment option for cecal MALT lymphoma.

[Unpleasant Journey from Helicobacter pylori-associated Gastritis to Gastric Cancer: Cancer Prevention by Taking a Detour]

As a commensal or a pathogen, Helicobacter pylori can change the balance of a complex interaction that exists among gastric epithelial cells, microbes, and their environment. Therefore, unraveling this complex relationship of these mixtures can be expected to help prevent cancer as well as troublesome unmet medical needs of H. pylori infection. Though gastric carcinogenesis is a multi-step process, precancerous lesion can be reversible in the early phase of mucosal damage before reaching the stage of no return. However, biomarkers to predict rejuvenation of precancerous atrophic gastritis have not been identified yet and gastric cancer prevention is still regarded as an impregnable fortress. However, when we take the journey from H. pylori-associated gastritis to gastric cancer, it provides us with the clue for prevention since there are two main preventive strategies: eradication and anti-inflammation. The evidence supporting the former strategy is now ongoing in Japan through a nation-wide effort to eradicate H. pylori in patients with chronic gastritis, but suboptimal apprehension to increasing H. pylori resistance to antibiotics and patient non-compliance still exists. The latter strategy has been continued in the author'sresearch center under siTRP (short-term intervention to revert premalignant lesion) strategy. By focusing on the role of inflammation in the development of H. pylori-associated gastric carcinogenesis, this review is intended to explain the connection between inflammation and gastric cancer. Strategies on H. pylori eradication, removal of inflammation, and reverting preneoplastic lesion will also be introduced. In the end, we expect to be able to prevent gastric cancer by take a detour from the unpleasant journey, i.e. from H. pylori-associated gastritis to gastric cancer.

A pilot study of confocal laser endomicroscopy for diagnosing gastrointestinal mucosa-associated lymphoid tissue (MALT) lymphoma

BACKGROUND

Patients with gastrointestinal mucosa-associated lymphoid tissue (MALT) lymphoma require lifelong endoscopic follow-up. This study aimed to establish and evaluate confocal laser endomicroscopy (CLE) criteria for gastrointestinal MALT lymphoma.

METHODS

This prospective trial was conducted after IRB approval at the Medical University of Vienna. Twenty-four consecutive patients (14 males and 10 females, median age 65 years) referred for staging or follow-up of (former) gastrointestinal MALT lymphoma underwent endosonography (EUS) and CLE including white light endoscopy (WLE) and conventional biopsy sampling of the upper gastrointestinal tract. CLE criteria of the disease were based on the first five patients with histologically proven MALT lymphoma. All CLE datasets were reviewed separately by two CLE experts. The diagnostic modalities were compared using conventional histology as the gold standard.

RESULTS

Sixty-two percentages had a positive diagnosis of MALT lymphoma based on histology. The sensitivity was 80 % for EUS (0.51-0.95), 100 % for WLE (0.75-1) and 93 % for CLE (0.66-1); the specificity was 67 % for EUS (0.31-0.91), 23 % for WLE (0.04-0.60) and 100 % for CLE (0.63-1). The agreement with histology was moderate for EUS (kappa 0.47, p = 0.02), fair for WLE (kappa 0.26, p = 0.06) and almost perfect for CLE (kappa 0.91, p < 0.01). Expert evaluation identified all but one case of MALT lymphoma with excellent interobserver agreement (kappa 0.89, p < 0.01). In the case missed by CLE, MALT lymphoma involvement was restricted to deep tissue structures.

CONCLUSIONS

Despite minor technical limitations, CLE is a promising alternative to conventional biopsy sampling in patients with gastrointestinal MALT lymphoma. CLINICALTRIALS.

GOV NUMBER

NCT01583699.

A retrospective international study on primary extranodal marginal zone lymphoma of the lung (BALT lymphoma) on behalf of International Extranodal Lymphoma Study Group (IELSG)

Primary lymphoma of the lung is a rare entity. Clinical features, optimal treatment, role of surgery and outcomes are not well defined, and the follow-up is variable in published data. Clinical data of 205 patients who were confirmed to have bronchus mucosa-associated lymphoid tissue lymphoma from December 1986 to December 2011 in 17 different centres worldwide were evaluated. Fifty-five per cent of the patients were female. The median age at diagnosis was 62 (range 28-88) years. Only 9% had a history of exposure to toxic substances, while about 45% of the patients had a history of smoking. Ten per cent of the patients had autoimmune disease at presentation, and 19% patients had a reported preexisting lung disease. Treatment modalities included surgery alone in 63 patients (30%), radiotherapy in 3 (2%), antibiotics in 1 (1%) and systemic treatment in 128 (62%). Patients receiving a local approach, mainly surgical resection, experienced significantly improved progression-free survival (p = 0.003) versus those receiving a systemic treatment. There were no other significant differences among treatment modalities. The survival data confirm the indolent nature of the disease. Local therapy (surgery or radiotherapy) results in long-term disease-free survival for patients with localized disease. Systemic treatment, including alkylating-containing regimens, can be reserved to patients in relapse after incomplete surgical excision or for patients with advanced disease. Copyright © 2015 John Wiley & Sons, Ltd.

Renal small B-cell lymphoma with plasmacytic differentiation presenting with monoclonal gammopathy and disseminated intravascular coagulation syndrome

Primary renal lymphomas are very rare. However, the kidney may be a site of metastasis, usually from a disseminated aggressive lymphoma. A 58-year-old woman was brought to the medical facility due to acute mental confusion, severe hypotension, septic shock, and signs of disseminated intravascular coagulation. Laboratory tests showed severe leukopenia, renal failure, altered liver function, and elevated serum lactate dehydrogenase levels. Protein electrophoresis revealed hypergammaglobulinemia with a monoclonal peak of IgG lambda. The clinical outcome was fulminant and the patient died less than 24 hours after admission. Autopsy revealed an indolent B-cell lymphoma with extensive plasmacytic differentiation infiltrating the right renal sinus and involving the submandibular and sublingual glands, cervical and peri-aortic lymph nodes, multiple microscopic foci in pituitary and adrenal glands, lung, breast, liver, thyroid, and bone marrow. Numerous IgG4-positive plasma cells were detected by immunohistochemistry although other histological features of IgG4-related disease were missing. There was also extensive hemorrhagic necrosis of the adrenal glands and purulent cystitis, which was probably responsible for the septic shock. The authors concluded that the kidney was most likely the primary site of the indolent lymphoma, as that was the site with the largest tumor mass. Infiltration of other organs was considered as dissemination of the disease. The differential diagnosis with mucosa-associated lymphoid tissue and lymphoplasmacytic lymphoma is discussed.

Eradication therapy is effective for Helicobacter pylori-negative gastric mucosa-associated lymphoid tissue lymphoma

Mucosa-associated lymphoid tissue (MALT) lymphomas are extra-nodal B-cell lymphomas arising from MALT, and the most commonly affected organ is the stomach. Helicobacter pylori (H. pylori) eradication therapy with proton-pump inhibitors and antibiotics is the first-line therapy for H. pylori-positive gastric MALT lymphomas, but the effectiveness of the therapy for H. pylori-negative gastric MALT lymphomas remains controversial. Hence, we aimed to evaluate the effectiveness of this eradication therapy for H. pylori-negative MALT lymphomas. The H. pylori infection status of 158 gastric MALT lymphoma patients followed in our unit was judged by urea breath test, rapid urease test, histology of the biopsy specimen taken from the stomach during endoscopy, and serum antibody against H. pylori. Seventeen patients that were negative for all four tests and did not have gastric mucosal atrophy were treated with antibiotic eradication therapy. The average age at diagnosis was 56.8 years old (range: 36-73 years), and the median follow-up period after H. pylori eradication in all 17 patients was 5.3 years (range: 0.3-12.7 years). Five patients (29.4%) achieved complete remission (CR) by eradication therapy alone. Comparison between the responding and non-responding patients revealed that the patients endoscopically diagnosed to have a single lesion of gastric MALT lymphoma were seen only in the responding group, whereas all non-responding patients had multiple lesions (P < 0.05). In conclusion, H. pylori eradication therapy achieved a favorable CR rate in H. pylori-negative gastric MALT lymphoma patients and could be considered as a first-line therapy, especially for patients with a single lesion.

Review of the molecular profile and modern prognostic markers for gastric lymphoma: how do they affect clinical practice?

Primary gastric lymphoma is a rare cancer of the stomach with an indeterminate prognosis. Recently, a series of molecular prognostic markers has been introduced to better describe this clinical entity. This review describes the clinical importance of several oncogenes, apoptotic genes and chromosomal mutations in the initiation and progress of primary non-Hodgkin gastric lymphoma and their effect on patient survival. We also outline the prognostic clinical importance of certain cellular adhesion molecules, such as ICAM and PECAM-1, in patients with gastric lymphoma, and we analyze the correlation of these molecules with apoptosis, angiogenesis, tumour growth and metastatic potential. We also focus on the host-immune response and the impact of Helicobacter pylori infection on gastric lymphoma development and progression. Finally, we explore the therapeutic methods currently available for gastric lymphoma, comparing the traditional invasive approach with more recent conservative options, and we stress the importance of the application of novel molecular markers in clinical practice.

Plasmacytic differentiation in MALT lymphomas following treatment with rituximab

Mucosa-associated lymphoid tissue (MALT) lymphomas are B cell neoplasms which commonly affect the gastrointestinal (GI) tract. Gastrointestinal MALT lymphomas rarely show plasmacytic differentiation (PCD), and limited data on the potential influence of the anti-CD20 antibody rituximab (R) on PCD exist in the current literature. We have retrospectively analyzed patients with GI MALT lymphomas treated with R-containing regimens because restaging is routinely performed by repeated biopsies with pathohistological response assessment. Twenty-one patients with GI MALT lymphoma were identified to have undergone R-containing therapy. In 19 patients, the lymphoma originated in the stomach, while the colon was the primarily affected organ in two cases. Four patients received R monotherapy and 17 combinations of R with various chemotherapeutic agents. Only two patients with gastric MALT lymphoma had PCD before initiation of therapy. In 7 of 19 patients (37%) without PCD at diagnosis, restaging revealed PCD after or while on treatment with R-containing regimens. Out of these seven patients, only one patient had a complete response as opposed to 10/12 without PCD. These data suggest that R or R-containing treatment regimens may not optimally eradicate the plasma cell component and thus lead to PCD in patients with GI MALT lymphoma. In view of this, rebiopsy and histological re-assessment appear mandatory in patients failing/relapsing after R-containing regimens.

Subcutaneous dissemination pattern in extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue lymphoma

BACKGROUND

Mucosa-associated lymphoid tissue (MALT) lymphoma is among the most common forms of extranodal lymphomas, but little is known about subcutaneous involvement in patients with non-primary cutaneous marginal zone lymphomas.

DESIGN AND METHODS

Patients with MALT lymphoma diagnosed and treated at our institution between 1999 and 2010 were analyzed for subcutaneous deposits from MALT lymphoma diagnosed in another organ. Histological, clinical and genetic findings were assessed.

RESULTS

Among 216 patients with MALT lymphoma, 12 had subcutaneous deposits from MALT lymphoma (5.5%). In two patients, these lesions were present at diagnosis, while they constituted the site of relapse at an interval between 5 to 144 months in the remaining cases. Interestingly, nine of the 12 patients with subcutaneous deposits had originally been diagnosed with MALT lymphoma of the ocular adnexa (total number=51; 20%), and the other three had MALT lymphoma in the breast (total number=5; 60%). None of the patients with gastric (n=86), salivary gland (n=32) or pulmonary (n=19) MALT lymphomas had subcutaneous involvement during a median follow-up time of 87 months (range; 4 to 119 months).

CONCLUSIONS

Our data show that subcutaneous MALT lymphoma involvement is a rare event in patients with prior non-cutaneous extranodal marginal zone lymphoma. However, it seems to be almost exclusively associated with MALT lymphoma of the ocular adnexa and the breast, suggesting as yet undefined interactions between potentially embryonically related organ systems.

Primary thyroid mucosa-associated lymphoid tissue lymphoma; a clinicopathological study of seven cases

PURPOSE

Primary thyroid mucosa-associated lymphoid tissue (MALT) lymphoma is a very rare subgroup of thyroid lymphoma, accounting for about 6 to 28% of all primary thyroid lymphomas. The purpose of this study was to evaluate its clinicopathological features and treatment outcomes.

METHODS

We identified seven patients with thyroid MALT lymphoma who were treated between January 1997 and December 2007, and reviewed their clinicopathological features and follow-up outcomes.

RESULTS

There were five female and two male patients, and their mean age was 73 years. All patients presented with palpable neck mass. Two patients had hoarseness and dyspnea. All patients had a history of Hashimoto's thyroiditis with a mean of 175 months. Malignant lymphoma was suspected in only three patients using core needle biopsy. Four patients underwent thyroidectomy in the absence of preoperative pathologic confirmation, and histologic diagnosis was obtained after surgery. As initial treatment, complete surgical resection was performed in five patients, radiotherapy in one, and a combination of chemotherapy and radiotherapy in one. Six patients were alive for the mean follow-up period of 66 months and one patient died of unrelated causes. There were neither recurrences nor disease-specific mortalities.

CONCLUSION

When primary thyroid MALT lymphoma occurs in the thyroid or is confined to the neck, it responds well to local treatment such as surgical resection and external beam radiation therapy.

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.

Treatment of extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue with fludarabine: effect on tumor microenvironment

Gastric Helicobacter pylori (HP) positive extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) develops during chronic antigenic stimulation with specific T-cell help. Chemotherapy that acts both on the malignant B-cells and on T-cells in the microenvironment, i.e. nucleoside analogs, might therefore be an attractive treatment. In 14 patients with gastric MALT lymphoma treated with fludarabine, alterations in T-cell subsets were studied in subsequent peripheral blood samples and in gastric biopsies. Treatment with fludarabine resulted in a steep decrease in T-cell subsets in peripheral blood samples. By contrast no decrease in T-cell populations was observed in subsequent gastric biopsy samples and a moderate increase was observed in relative infiltration with CD3 +, CD4 + and CD8 + cells. In addition an increase in density of FOXP3 + cells (i.e. Tregs) was seen (p = 0.047). These alterations in different T-cell subsets were not observed in gastric biopsy samples of patients treated with HP-eradication only.

Tumor-associated macrophages as major source of APRIL in gastric MALT lymphoma

Lymphoid hyperplasia of gastric mucosa associated with Helicobacter pylori (HP) infection represents a preneoplastic condition of the mucosa associated lymphoid tissue (MALT), which may evolve to a B-cell lymphoma. While it is well established that the initial neoplastic proliferation of B cells is antigen-driven and dependent on the helper activity of HP-specific T cells, it needs to be elucidated which cytokine or soluble factor(s) promote B-cell activation and lymphomagenesis. Herein, we originally report that gastric MALT lymphoma express high levels of a proliferation inducing ligand (APRIL), a novel cytokine crucial in sustaining B-cell proliferation. By immunohistochemistry, we demonstrate that APRIL is produced almost exclusively by gastric lymphoma-infiltrating macrophages located in close proximity to neoplastic B cells. We also show that macrophages produce APRIL on direct stimulation with both HP and HP-specific T cells. Collectively, our results represent the first evidence for an involvement of APRIL in gastric MALT lymphoma development in HP-infected patients.

Chlamydia psittaci Infection in nongastrointestinal extranodal MALT lymphomas and their precursor lesions

Extranodal marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT) are associated with various infectious pathogens. We analyzed the presence of Chlamydia psittaci, Chlamydia pneumoniae, and Chlamydia trachomatis DNA in 47 nongastrointestinal and 14 gastrointestinal MALT lymphomas, 37 nonmalignant control samples, and 27 autoimmune precursor lesions by polymerase chain reaction amplification and direct sequencing. In 47 nongastrointestinal MALT lymphomas, 13 (28%) were positive for C psittaci DNA compared with 4 (11%) of 37 nonmalignant control samples (P = .09). C psittaci was detected at variable frequencies in MALT lymphomas of different sites: lung, 100% (5/5; P < .01); thyroid gland, 30% (3/10; P > .05); salivary gland, 13% (2/15; P > .05); ocular adnexa, 15% (2/13); and skin, 25% (1/4). Of 27 autoimmune precursor lesions (11 Hashimoto thyroiditis and 16 Sjögren syndrome), 11 (41%) contained C psittaci DNA. Only 1 (7%) of 14 gastrointestinal MALT lymphomas was positive for C psittaci. All specimens were negative for C trachomatis and C pneumoniae. Besides ocular adnexal lymphomas, C psittaci infection is associated with nongastrointestinal MALT lymphomas and autoimmune precursor lesions, suggesting possible involvement of C psittaci-induced antigenic-driven MALT lymphomagenesis.

Efficacy of rituximab in gastric diffuse large B cell lymphoma patients

AIM: To evaluate retrospectively the efficacy of rituximab plus chemotherapy in gastric diffuse large B cell lymphoma (DLBCL).

METHODS: Sixty patients (median age: 58 years) with histologically confirmed gastric DLBCL treated at four Italian institutions between 2000 and 2007, were included in this analysis. Patients were selected by stage (I-IV, Lugano staging system), European Cooperative Oncology Group performance status (0-2) and treatment strategies. Treatment strategies were chemotherapy alone (group A, n = 30) [scheduled as cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) and CHOP-like], and chemotherapy combined with rituximab (group B, n = 30). The primary end point of the study was complete response (CR) rate; the secondary end points were disease-free survival (DFS) at 5 years and overall survival (OS).

RESULTS: Median follow-up was 62 mo (range: 31-102 mo). We observed a significant difference between the two groups (A vs B) in terms of CR [76.6% (23/30) vs 100%, P = 0.04) and DFS at 5 years [73.3% (22/30) vs 100%, P = 0.03). To date, 19 group A (63.3%) patients are alive and 11 have died, while all group B patients are alive. No significant differences in toxicity were observed between the two groups.

CONCLUSION: Rituximab in combination with chemotherapy improves CR rate, DFS and OS. Further prospective trials are needed to confirm our results.

Gastrointestinal dissemination of mucosa-associated lymphoid tissue lymphoma: computed tomographic findings

OBJECTIVE

To describe the computed tomographic findings of mucosa-associated lymphoid tissue (MALT) lymphoma with gastrointestinal (GI) tract dissemination.

METHODS

We retrospectively reviewed the computed tomographic findings for the location, morphology, contrast enhancement, and continuity of the involved bowel segment with ancillary findings in 10 patients with MALT lymphoma involving multiple GI tracts.

RESULTS

MALT lymphoma involved a total of 31 bowel segments. The gastric lesions appeared as segmental (n = 4) or diffuse (n = 1) wall thickening and the small- or large-intestinal lesions as circumferential wall thickening (n = 11) or localized polypoid mass (n = 8) with homogeneous and isoattenuating or hypoattenuating enhancement. Continuity of the involved bowel segment was present in 6 patients, bowel perforation in 1, lymphadenopathy in 8, and hepatosplenomegaly in 4.

CONCLUSIONS

Despite its rarity, MALT lymphoma can disseminate into the GI tract in the form of circumferential bowel wall thickening or localized polypoid mass with or without gastric involvement.

Gastric low-grade mucosal-associated lymphoid tissue-lymphoma: Helicobacter pylori and beyond

The stomach is the most frequently involved site for extranodal lymphomas, accounting for nearly two-thirds of all gastrointestinal cases. It is widely accepted that gastric B-cell, low-grade mucosal-associated lymphoid tissue (MALT)-lymphoma is caused by Helicobacter pylori (H. pylori) infection. MALT-lymphomas may engender different clinical and endoscopic patterns. Often, diagnosis is confirmed in patients with only vague dyspeptic symptoms and without macroscopic lesions on gastric mucosa. H. pylori eradication leads to lymphoma remission in a large number of patients when treatment occurs at an early stage (I-II₁). Neoplasia confined to the submucosa, localized in the antral region of the stomach, and without API2-MALT1 translocation, shows a high probability of remission following H. pylori eradication. When both bacterial infection and lymphoma recur, further eradication therapy is generally effective. Radiotherapy, chemotherapy and, in selected cases, surgery are the available therapeutic options with a high success rate for those patients who fail to achieve remission, while data on immunotherapy with monoclonal antibodies (rituximab) are still scarce. The 5-year survival rate is higher than 90%, but careful, long-term follow-up is required in these patients since lymphoma recurrence has been reported in some cases.

Role of chemotherapy in gastric MALT lymphoma, diffuse large B-cell lymphoma and other lymphomas

Primary gastrointestinal lymphomas are relatively common, with the large majority occurring in the stomach. In the commonest histological subtype, i.e. diffuse large B-cell lymphoma (DLCBL), chemotherapy has widely been applied in the past, either following surgery or - in more recent years - as part of conservative management in combination with radiotherapy. Relatively little data, however, exist for chemotherapy as sole treatment modality in localised gastric DLBCL, which nevertheless are highly promising and suggest that combination therapy might overtreat a substantial proportion of patients. In gastric MALT-lymphoma, the use of chemotherapy has been restricted either to patients with a priori disseminated disease or individuals judged to be at high risk or failing local treatment approaches. Only a few prospective phase II studies have been performed, and one controlled trial has shown that chemotherapy was superior in terms of event free survival at ten years when compared to radiation and surgery. These suggest that systemic treatment approaches might be highly effective both in gastric DLBCL as well as MALT-lymphoma, and the scope of this article is to briefly summarize current data on chemotherapy in gastric and GI-lymphomas according to histologic subtypes.

[A case of primary sigmoid colon mucosa-associated lymphoid tissue lymphoma]

The gastrointestinal (GI) tract is the most frequently involved site of mucosa-associated lymphoid tissue (MALT) lymphoma. Stomach is the most common site of involvement among the GI tract. However, MALT lymphoma of the large intestine is rare. A diagnosis is established by pathological examination of the surgical or endoscopic specimens. A 72-year-old man with low abdominal pain was diagnosed as a sigmoid MALT lymphoma, which was noted as an obstructing mass in a colonoscopic examination. A left hemicolectomy was performed, and the patient has had no recurrence postoperatively without any chemotherapy.

Transformation of MALT lymphoma to pure plasma cell histology following treatment with the anti-CD20 antibody rituximab

Mucosa associated lymphoid tissue (MALT) lymphoma is a relatively common lymphoma arising from marginal-zone B-cells which are closely related to plasma cells. As opposed to the large majority of plasma cells, MALT lymphoma cells express CD20, and the anti-CD20 antibody rituximab has been reported as active treatment in patients with MALT lymphoma. We present a patient with MALT lymphoma involving stomach and lung which transformed to a pure plasma cell tumor after therapy with rituximab. This observation again supports the close association between the cell of origin of MALT lymphoma and plasma cells, suggesting that "plasmacytoma of the GI-tract" as anecdotally reported may in fact be a MALT lymphoma with extreme plasmacytic differentiation. In addition, our findings suggest that MALT lymphomas with plasmacytic differentiation might have a different 18F-FDG uptake as compared to classical MALT lymphoma.

Lack of an association betweenChlamydia psittaciand ocular adnexal lymphoma

The objective of this study was to assess whether there is PCR evidence for C. psittaci DNA in ocular adnexal lymphoma specimens collected in an academic institution in the U.S. This was a retrospective, single-center study of patients from 1994 - 2004. We used 28 ocular adnexal lymphoma biopsy specimens from adult patients, 16 control lymphoma specimens from patients with systemic lymphomas not involving the ocular adnexa, and five control benign adnexal tissue samples. The presence of C. psittaci DNA was investigated by polymerase chain reaction (PCR) in each group. Two different assays were utilized: (1) conventional PCR/gel based assay targeting a 111-bp fragment of the 16S gene and (2) a real-time PCR assay amplifying a 148-bp portion of the 16S gene with detection via a specific fluorescent probe. Amplification was carried out to 60 cycles. Positive controls consisted of isolated DNA from C. psittaci strains VS1, CP3, and FP. A human DNA internal control was used to assess sample DNA quality and amplification success. Mean outcome measure was the presence of C. psittaci DNA. Using both assays, all patient samples in all categories yielded negative results. Both assays detected C. psittaci DNA from isolated strains. Internationally, Chlamydia psittaci has been associated with ocular adnexal lymphomas with great variability. Similar to several other recent studies in the USA, our study could not confirm the presence of C. psittaci in ocular adnexal lymphomas. Differences in the prevalence of C. psittaci infection in various geographic regions or technical differences in the application of the assays may underlie the variability in the association between C. psittaci and ocular adnexal lymphoma.

Clinicopathological comparison of the World Health Organization/Wotherspoon score to the Groupe d'Etude des Lymphomes de l'Adult grade for the post-treatment evaluation of gastric mucosa-associated lymphoid tissue lymphoma

BACKGROUND AND AIM

The World Health Organization (WHO) has adopted criteria for the histological differential diagnosis of gastric extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (GML) based on the criteria proposed by Wotherspoon in 1993 (WHO/Wotherspoon score). These histological criteria are commonly used by pathologists for initial diagnoses, but have not been adopted uniformly for the post-treatment evaluation of GML. In 2003, the Groupe d'Etude des Lymphomes de l'Adult (GELA) proposed a new histological grading system (GELA grade) in preference to use of the WHO/Wotherspoon score for post-treatment evaluation. In the present study, we compared the WHO/Wotherspoon and GELA systems to examine which histological criterion is better for post-treatment evaluation.

METHODS

Fourteen cases of GML under long-term follow up were initially diagnosed according to the WHO criteria with detailed immunohistology, and were periodically evaluated with both histological criteria after anti-Helicobacter pylori treatment. They were also evaluated based on histological stromal changes accompanying the disappearance of lymphoma tissue.

RESULTS

The study showed strong similarities between the WHO/Wotherspoon and GELA systems and no clear advantage of either system for post-treatment evaluation. The GELA grade could not be used for the evaluation of changes in the degree of lymphoma infiltration from pre- to post-treatment because the four-item scale is not comparable with the formal six-point WHO/Wotherspoon scale. Stromal changes in the lamina propria, including an empty appearance and fibrosis, were correlated with lymphoma reduction after treatment and appear to be good indicators for post-treatment evaluation.

CONCLUSION

We propose the utilization of the WHO/Wotherspoon score accompanied by the assessment of stromal changes for the post-treatment evaluation of GML.

Heat-shock proteins in infection-mediated inflammation-induced tumorigenesis

Inflammation is a necessary albeit insufficient component of tumorigenesis in some cancers. Infectious agents directly implicated in tumorigenesis have been shown to induce inflammation. This process involves both the innate and adaptive components of the immune system which contribute to tumor angiogenesis, tumor tolerance and metastatic properties of neoplasms. Recently, heat-shock proteins have been identified as mediators of this inflammatory process and thus may provide a link between infection-mediated inflammation and subsequent cancer development. In this review, the role of heat-shock proteins in infection-induced inflammation and carcinogenesis will be discussed.

Classification of lymphoid neoplasms: the microscope as a tool for disease discovery

In the past 50 years, we have witnessed explosive growth in the understanding of normal and neoplastic lymphoid cells. B-cell, T-cell, and natural killer (NK)-cell neoplasms in many respects recapitulate normal stages of lymphoid cell differentiation and function, so that they can be to some extent classified according to the corresponding normal stage. Likewise, the molecular mechanisms involved the pathogenesis of lymphomas and lymphoid leukemias are often based on the physiology of the lymphoid cells, capitalizing on deregulated normal physiology by harnessing the promoters of genes essential for lymphocyte function. The clinical manifestations of lymphomas likewise reflect the normal function of lymphoid cells in vivo. The multiparameter approach to classification adopted by the World Health Organization (WHO) classification has been validated in international studies as being highly reproducible, and enhancing the interpretation of clinical and translational studies. In addition, accurate and precise classification of disease entities facilitates the discovery of the molecular basis of lymphoid neoplasms in the basic science laboratory.

Gene expression profiling in Helicobacter-induced MALT lymphoma with reference to antigen drive and protective immunization

We have previously shown that long-term infection of BALB/c mice with gastric Helicobacter species results in the development of histopathological lesions that resemble those seen in patients diagnosed with gastric mucosa associated lymphoid tissue (MALT) lymphoma. This paper describes analysis of this disease at the molecular level through the use of microarray technology and immunohistochemical staining. We were able to monitor the genetic changes in the gastric mucosa characterized by distinct transcriptional signatures and correlate these with histological changes as the infection progressed from a chronic inflammatory infiltrate through to MALT lymphoma. This model system also enabled us to further dissect the role of antigen presentation and prophylactic immunization in the disease process. Antimicrobial therapy to eradicate the antigen correlated with significant reduction in pathology and major changes in the gene expression profile. Subsequent reintroduction of the antigen resulted in rapid tumor development which correlated with an increase in aggressively proliferating cells and changes in the cellular composition of the tumor. The response in vaccinated animals showed that the protected animals exhibited a strikingly different transcriptional profile compared to those of non-protected or control mice, indicating that the vaccination targeted the appropriate site leaving a long-lasting signature. The genes which were most significantly up-regulated included a number of adipocyte-specific factors, such as fat-cell specific cytokines and adipocyte surface markers. This study allowed for us to highlight the significance of antigen presentation in this disease and to hypothesis mechanisms associated with protective immunity.

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.

Morphologic Features of 115 Lymphomas of the Orbit and Ocular Adnexa Categorized According to the World Health Organization Classification: Are Marginal Zone Lymphomas in the Orbit Mucosa-Associated Lymphoid Tissue–Type Lymphomas?

Context.—Marginal zone lymphomas (MZLs) are the most common lymphomas encountered in the orbit and ocular adnexa. The accurate categorization of these lymphomas is critical to avoid undertreatment or overtreatment.

Objective.—To identify features of orbital MZLs that distinguish them from other lymphomas and reactive lymphoid infiltrates and support the categorization of orbital MZL as mucosa-associated lymphoid tissue (MALT)–type MZLs.

Design.—Biopsies from 149 patients with lymphoid lesions of ocular adnexa were examined. Additional immunohistochemical stains and fluorescence in situ hybridization study for the MALT1 locus were performed in selected cases, and patient charts were reviewed.

Results.—A total of 115 lymphomas and 34 reactive infiltrates were identified, of which B-cell lymphomas constituted 92% and MZLs constituted 54% of all lymphomas. Certain clinical features (young age, race, bilaterality) favored a reactive infiltrate, but none were diagnostic. Histologic features, such as infiltrative lesions, reactive B-cell follicles, and lymphoepithelial lesions, overlapped between reactive infiltrates and conjunctival MZL. In contrast to conjuctival MZL, orbital MZL infrequently showed reactive follicles, rarely showed epithelial tissue, and did not show lymphoepithelial lesions. Cytogenetic abnormality involving the MALT1 locus was demonstrated in only 15% of ocular adnexal MZLs.

Conclusion.—Many MZLs of orbital soft tissue lack key features associated with MALT-type MZL, and the designation MALT lymphoma should be avoided in their diagnosis.

Higher rates of t(11;18) in Chinese patients with transformed type of MALT lymphoma suggest novel pathways for progression of the disease

To detect the t(11;18) chromosome translocation in different stages of mucosa-associated lymphoid tissue (MALT) lymphoma, we established a RT-PCR method by adopting three new primer pairs and using the RNA extracted from the paraffin tissues to amplify the t(11;18) fusion gene API2-MALT1 in shorter lengths. Our results showed five key findings, which are (a) higher detection rates of t(11;18) (21.13%) in Chinese patients with transformed MALT lymphoma, (b) lower detection rates of t(11;18) in stomach MALT lymphoma, (c) different organ localizations of MALT lymphoma in Chinese patients, (d) higher nuclear expression rates of Bcl-10 in low grade MALT (51.72%), and (e) lower response rates (50% CR, and 50% PR) to anti-H.-pylori therapy. These findings suggest novel pathways for low-grade MALT lymphoma to be progressed into transformed MALT lymphoma. This study also suggests that amplification of shorter length of PCR products from the paraffin-fixed tissues increases sensitivity, which is significant in improving the selection of the therapeutic regimen and assessing the prognosis of the disease.

Primary MALT Type Skin Lymphoma—Is ‘Wait and See’ a Possible Strategy?

Primary cutaneous lymphomas are the second most common site of extranodal non-Hodgkin lymphoma. A specifically type named extranodal marginal zone B-cell lymphomas are indolent low-grade neoplasma.

We report a case of a 42-year-old white man with multiple subcutaneous tumors located on the trunk and neck. The histopathological exam showed a non-epidermotropic, dense lymphocytic infiltrate. Histologic, immunohistochemical and cytologenetic analysis diagnosed primary cutaneous B-cell lymphoma MALT type. Investigation for other extranodal MALT lymphoma gastrointestinal tract, lung, salivary and thyroid glands was negative. The patient refused radiotherapy, but he accepted every 6 months close follow-up. Over a seven years period, we noticed a progressively disappearance of the skin lesions.

The necessity of aggressive treatment of this disease with excellent prognosis is discussed.

The treatment necessity of primary cutaneous B-cell lymphoma MALT type is discussed.

Synchronous Mucosa-Associated Lymphoid Tissue Lymphoma and Gastrointestinal Stromal Tumor of the Stomach Presenting with Gastric Bleeding

We report an extraordinarily rare case of synchronous mucosa-associated lymphoid tissue lymphoma and gastrointestinal stromal tumor of the stomach. An 80-year-old man presented with gastric bleeding. Gastroscopy showed an ulcerative lesion and a submucosal tumor at the upper corpus of the stomach. The ulcerative lesion was proven by biopsy to be mucosa-associated lymphoid tissue lymphoma, but the submucosal tumor could not be diagnosed. Due to the repeating episodes of massive gastric bleeding, a total gastrectomy with lymphadenectomy was performed. After the operation, the submucosal tumor was pathologically proven to be a gastrointestinal stromal tumor. In this case, synchronous occurrence of mucosa-associated lymphoid tissue lymphoma and gastrointestinal stromal tumor seems to be coincidental rather than related with the same pathogenic triggering. Surgical resection of the stomach provided an accurate diagnosis and an effective treatment.

Meta-analyses of the association between Chlamydia psittaci and ocular adnexal lymphoma and the response of ocular adnexal lymphoma to antibiotics

BACKGROUND

There are conflicting reports regarding the association between Chlamydia psittaci (Cps) and ocular adnexal lymphoma (OAL) and the efficacy of antibiotics for OAL. In the current study, the authors attempted to clarify the association between Cps and OAL and the efficacy of antibiotics for OAL.

METHODS

Two meta-analyses were conducted. One focused on the association between Cps and OAL across geographic regions and among different studies. The other was a meta-analysis of the response of OAL to antibiotic treatment.

RESULTS

The authors identified 11 studies of Cps prevalence that included 458 cases of OAL from 10 different countries. Four studies regarding the efficacy of oral antibiotics to treat OAL were found. One hundred four of the 458 OAL specimens (23%) and 87 of the 346 mucosa-associated lymphoid tissue (MALT) lymphoma specimens (25%) were found to be positive for Cps. Ninety-four of the 104 Cps-positive OAL specimens (90%) came from 3 of the 11 studies. There was wide variation noted between geographic regions and even between studies from the same geographic region with regard to the rate of Cps positivity. The 4 studies concerning the efficacy of antibiotics for OAL were from Italy, Austria, Taiwan, and the U.S. and included 42 patients. Twenty patients (48%) achieved some response (complete response in 8 patients, partial response in 8 patients, and minimal response in 4 patients). Twenty patients also had stable disease, and 2 patients progressed during antibiotic therapy. Objective documentation of response (radiographs or clinical slit-lamp photographs) was available for only 3 of the 42 patients. Seven additional patients developed disease recurrence after their initial response or stable disease after antibiotic therapy; 6 of these cases of disease recurrence occurred during the first 12 months of follow-up.

CONCLUSIONS

The findings of the current study suggest a striking variability in the association between Cps and OAL across geographic regions and even between studies from the same geographic regions. The overall rate of Cps positivity in our meta-analysis (23%) was much lower than that reported in the original report. The current study findings also suggest that antibiotics have variable efficacy against OAL. Future prospective trials with standard objective response criteria and a longer follow-up period would be necessary to evaluate the role of antibiotics in the treatment of OAL further.

Marginal-zone lymphoma

The term marginal-zone lymphoma (MZL) encompasses three closely related lymphoma subtypes, namely the "low-grade B-cell lymphoma of MALT type" currently named MALT lymphoma, the "nodal marginal-zone B-cell lymphoma" and a provisional entity in the REAL classification named "primary splenic MZL with or without villous lymphocytes". These entities display different characteristics, with evident clinical and biological variations according to the organ where the lymphoma arises. Marginal-zone B-cells are functionally heterogeneous and may differ with respect to the pattern of somatic hypermutation in their Ig variable genes. Sequence and mutation analysis of the rearranged Ig heavy chain variable genes and that somatic mutations pattern indicate that MZL may arise from different subsets of marginal-zone B-cells. Pathogenesis of these groups of lymphomas is correlated to chronic infections, like Helicobacter pylori, hepatitis C virus, Campylobacter jejuni, Chlamydia psittaci and Borrelia burgdorferi. Several therapeutic strategies against these malignancies exist. Surgical resection, radiotherapy and alkylating agent-based chemotherapy constitute standard approaches, while antimicrobial therapies, anti-CD20 therapy and new forms of immunotherapy constitute interesting experimental approaches. However, prospective trials on these malignancies are rare and universally accepted therapeutic guidelines do not exist. MZLs constitute an exciting investigational setting both from molecular and clinical points of view.

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.

Therapy of gastric mucosa-associated lymphoid tissue lymphoma

Mucosa-associated lymphoid tissue (MALT) lymphoma is a relatively common lymphoma and comprises approximately 7% of all newly diagnosed non-Hodgkin's lymphoma. It is mainly located in the stomach and has become a focus of interest due to its unique pathophysiological link with Helicobacter pylori (HP) and the consecutive response to HP eradication therapy. In view of this, HP eradication has become standard treatment for patients with localised disease, and recent data have suggested that HP-negative patients might benefit from antibiotic treatment. In case of non-response, however, the standard approach in such patients is unclear. Both radiation and chemotherapy have shown promising results, and at present there is only one randomised study, which nevertheless suggests chemotherapy as management of choice. The objective of this review is, therefore, to summarise and evaluate the data available for treatment of gastric MALT lymphoma and to highlight potential focus for further research.

MALT lymphoma in patients with autoimmune diseases: a comparative analysis of characteristics and clinical course

MALT lymphoma, especially of extragastric origin, is thought to be associated with an underlying autoimmune disease (AD) in a significant proportion of patients. No systematic assessment of the clinical characteristics of MALT lymphoma arising in AD as opposed to patients without AD has been performed so far. Therefore, all patients diagnosed and treated for MALT lymphoma at our institution have prospectively undergone routine clinical and serological assessment for AD since 1997. In total, 158 patients were available for analysis, and 61 out of 158 patients (39%) were diagnosed with an underlying AD. Patients with AD were predominantly women and significantly younger at lymphoma diagnosis (56 versus 67 years, P=0.004), with a significantly higher rate of extragastric lymphomas (P=0.012). Furthermore, lymphomas in these patients showed a lower frequency of trisomy 3 (P=0.04) and a significantly lower response rate to Helicobacter pylori eradication therapy in the case of gastric lymphomas (P=0.03). All other parameters including estimated median time to relapse were comparable between both groups. Our data suggest that patients with AD develop MALT lymphoma significantly earlier in life. The clinical course, however, does not appear to be adversely influenced by the presence of AD, as neither rate of relapse nor times to relapse or survival are significantly different.

Diagnosis of Helicobacter pylori: invasive and non-invasive tests

Helicobacter pylori infection can be diagnosed by invasive techniques requiring endoscopy and biopsy (e.g. histological examination, culture and rapid urease test) and by non-invasive techniques, such as serology, the urea breath test, urine/blood or detection of H. pylori antigen in stool specimen. Some non-invasive tests, such as the urea breath test and the stool antigen test, detect active infection: these are called 'active tests'. Non-invasive tests (e.g. serology, urine, near-patient tests) are markers of exposure to H. pylori but do not indicate if active infection is ongoing; these are 'passive tests'. Non-invasive test-and-treat strategies are widely recommended in the primary care setting. The choice of appropriate test depends on the pre-test probability of infection, the characteristics of the test being used and its cost-effectiveness.