Treatment outcome of localized Helicobacter pylori-negative low-grade gastric MALT lymphoma

H pylori-Negative MALT-Associated Extranodal Marginal Zone Lymphoma: A Comprehensive Case Report and Literature Review

Extranodal marginal zone B-cell lymphoma (ENMZL) of mucosa-associated lymphoid tissue (MALT), a rare subtype of B-cell lymphoma, is typically associated with Helicobacter pylori (H pylori) infection, especially in gastric cases. However, this article presents 2 unique cases of H pylori-negative colonic ENMZL, challenging the conventional understanding of the disease. The first case involves an 80-year-old male diagnosed with Stage 1E ENMZL in the descending colon, and the second describes a 74-year-old male with sigmoid colon ENMZL. Both cases lacked H pylori infection, adding complexity to their management. Accompanying these case studies is a comprehensive literature review, delving into the epidemiology, pathology, clinical features, diagnosis, and treatment of H pylori-negative ENMZL, with a focus on gastrointestinal involvement. This review highlights the importance of considering H pylori-negative cases in ENMZL diagnosis and management, illustrating the need for further research and individualized treatment approaches in this uncommon lymphoma subtype.

Bacteria in cancer initiation, promotion and progression

Cancer cells originate from a series of acquired genetic mutations that can drive their uncontrolled cell proliferation and immune evasion. Environmental factors, including the microorganisms that colonize the human body, can shift the metabolism, growth pattern and function of neoplastic cells and shape the tumour microenvironment. Dysbiosis of the gut microbiome is now recognized as a hallmark of cancer by the scientific community. However, only a few microorganisms have been identified that directly initiate tumorigenesis or skew the immune system to generate a tumour-permissive milieu. Over the past two decades, research on the human microbiome and its functionalities within and across individuals has revealed microbiota-focused strategies for health and disease. Here, we review the evolving understanding of the mechanisms by which the microbiota acts in cancer initiation, promotion and progression. We explore the roles of bacteria in gastrointestinal tract malignancies and cancers of the lung, breast and prostate. Finally, we discuss the promises and limitations of targeting or harnessing bacteria in personalized cancer prevention, diagnostics and treatment.

Five-year Progress of Gastric MALT Lymphoma Presenting as Gastric Outlet Obstruction

This paper reports a 70-year-old female with gastric extranodal marginal zone B cell lymphoma of mucosa-associated lymphoid tissue (gastric MALT lymphoma) as a rare case of gastric outlet obstruction. Five years earlier, she initially presented with weight loss and anemia. Esophagogastroduodenoscopy (EGD) revealed multiple gastric and duodenal ulcers with a pyloric deformity, while histology revealed chronic active inflammation and a Helicobacter pylori (H. pylori) infection. Three years earlier, she underwent EGD per the National Cancer Screening Program and was diagnosed with antral and duodenal ulcers. A forceps biopsy specimen from one of the ulcers showed the findings of gastric MALT lymphoma, but she did not visit the hospital for proper management. She visited complaining of a loss of appetite. EGD revealed a gastric outlet obstruction (GOO) caused by antral deformity and pyloric narrowing. A staged workup with CT and PET revealed full-layered, encircling antral wall thickening and several enlarged mesenteric lymph nodes. She was finally diagnosed with a gastric MALT lymphoma at Ann Arbor stage I1E with translocation t(11;18). She was treated with palliative surgery for GOO and systemic chemotherapy with a CHOP regimen. This paper reports a gastric MALT lymphoma that progressed from superficial mucosal lesions to an overt mass with regional lymph node metastasis for five years.

Primary hepatic lymphoma of MALT type mimicking hepatic adenoma treated by hepatectomy: a case report and literature review

Background

Primary hepatic lymphoma (PHL) is a rare malignant tumor. Extranodal marginal zone lymphoma of the mucosa-associated lymphoid tissue (MALT) is an indolent lymphoma occurring at extranodal sites. The stomach is the most common organ affected by MALT lymphoma, whereas liver-related lymphoma is rarely reported. Its atypical clinical presentation often delays the diagnosis. Owing to the rarity of PHL, identifying its optimal treatment still remains a challenge. Herein, we report a case of PHL of the MALT type mimicking hepatic adenoma that was treated by hepatectomy without chemotherapy and review the scarce literature. Our findings suggest that surgery is an alternative approach to cure patients with localized hepatic lymphoma.

Case summary

A 55-year-old woman was admitted to our hospital because of upper abdominal discomfort, and a liver lesion was detected by computed tomography. She did not have nausea, fever, fatigue, jaundice, weakness, night sweats, or weight loss before admission. And her previous medical history was unremarkable. There were no positive signs on physical examination. Based on her preoperative examination including magnetic resonance imaging, the liver lesion was suspected to be a hepatic adenoma; however, the possibility of it being a malignancy like hepatocellular carcinoma was not excluded. Therefore, a decision of resection of the lesion was made. During the operation, hepatectomy of segment 4b and cholecystectomy were performed. The patient recovered well; however, after postoperative pathological examination, the lesion was diagnosed as a hepatic lymphoma of MALT type. The patient was reluctant to undergo chemotherapy or radiotherapy. At 18-month follow-up, no significant recurrence was observed, indicating that the treatment had a curative effect.

Conclusion

Notably, primary hepatic lymphoma of MALT type is a rare, low-grade B-cell malignancy. Making an accurate preoperative diagnosis of this disease is usually difficult, and liver biopsy is an appropriate avenue to improve the diagnostic accuracy. In patients with a localized tumor lesion, hepatectomy followed by chemotherapy or radiotherapy should be considered to achieve better outcomes. Although this study describes an unusual type of hepatic lymphoma mimicking a benign tumor, it has its inherent limitations. More clinical studies are required to establish guidelines for the diagnosis and treatment of this rare disease.

Comprehensive Analysis of Gene Expression Profiling to Explore Predictive Markers for Eradication Therapy Efficacy against Helicobacter pylori-Negative Gastric MALT Lymphoma

Although radiotherapy is the standard treatment for Helicobacter pylori (Hp)-negative gastric mucosa-associated lymphoid tissue (MALT) lymphoma, eradication therapy using antibiotics and an acid secretion suppressor can sometimes induce complete remission. We explored predictive markers for the response to eradication therapy for gastric MALT lymphoma that were negative for both API2-MALT1 and Hp infection using comprehensive RNA sequence analysis. Among 164 gastric MALT lymphoma patients who underwent eradication therapy as primary treatment, 36 were negative for both the API2-MALT1 fusion gene and Hp infection. Based on eradication therapy efficacy, two groups were established: complete response (CR) and no change (NC). The Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that cancer-related genes and infection-related genes were highly expressed in the NC and CR groups, respectively. Based on this finding and transcription factor, gene ontology enrichment, and protein-protein interaction analyses, we selected 16 candidate genes for predicting eradication therapy efficacy. Real-time PCR validation in 36 Hp-negative patients showed significantly higher expression of olfactomedin-4 (OLFM4) and the Nanog homeobox (NANOG) in the CR and NC groups, respectively. OLFM4 and NANOG could be positive and negative predictive markers, respectively, for eradication therapy efficacy against gastric MALT lymphoma that is negative for both API2-MALT1 and Hp infection.

Long-Term Clinical Outcomes of Gastric MALT Lymphoma: A Nationwide Multicenter Study in Korea

Background

Treatment recommendations for gastric mucosa-associated lymphoid tissue (MALT) lymphoma are based on case series and expert opinions. Only a few previous studies have focused on the long-term outcomes of gastric MALT lymphoma, especially according to stage.

Methods

Patients diagnosed with gastric MALT lymphoma from January 2000 to December 2018 at nine university hospitals in Korea were included. Clinical data of medical history, endoscopic features, histological diagnosis, results of Helicobacter pylori (H. pylori) testing, stage, treatment conditions, and outcomes were collected.

Results

A total of 1,163 patients was enrolled, and 97.6% (n=1,038) of patients were diagnosed as stage IE. 10-year overall survival (OS) for the entire population was 99.1% and was better for patients in stage IE compared with patients in stage III/IV (p=0.002). The 10-year OS for H. pylori-positive patients was better than that of H. pylori-negative patients (p=0.022). Multivariate analyses revealed initial stage III/IV as a prognostic factor associated with over-all survival.

Conclusion

The majority of gastric MALT lymphoma patients are diagnosed at an early localized stage in Korea. The overall survival rate of gastric MALT lymphoma is excellent and is associated with the initial stage of the disease.

Helicobacter pylori Infection of the Gastric Mucosa and Ocular Adnexa-Lack of Association With Ocular Adnexal Lymphoma

PURPOSE

Helicobacter pylori could theoretically induce ocular adnexal lymphoma (OAL) via 2 mechanisms: the first is that of infection within the ocular adnexa and the second is that of infection within the gastric mucosa, leading to the malignant transformation of lymphocytes that migrate to the ocular adnexa, forming a primary "ectopic" cancer. This study investigated if an association exists between gastric H. pylori or ocular adnexal H. pylori and OAL.

METHODS

Prospective case-control study including cases with OAL and controls with nonlymphomatous pathologies. Gastric H. pylori infection was assessed via serologic antibody testing. Ocular adnexal infection was assessed via polymerase chain reaction testing for H. pylori and Chlamydia psittaci within ocular adnexal samples.

RESULTS

Seventy-two patients were enrolled, of whom 18 had lymphoma and 54 nonlymphomatous pathologies. H. pylori antibodies were present in 5 cases (28%) and 18 controls (33%) (95% CI, 0.24%-2.50%, p = 0.78). All ocular adnexal specimens were negative for H. pylori and C. psittaci infection. The only relevant statistically significant difference between cases and controls was a history of gastric ulcer (95% CI, 1.23%-44.80%, p = 0.03).

CONCLUSIONS

In the study's population, infection of gastric mucosa with H. pylori does not appear to influence the development of OAL. Also, H. pylori or C. psittaci infection within the ocular adnexa does not appear to influence the development of OAL. In the study's practice, authors do not recommend antibiotic administration or routine gastroscopy for patients with OAL. The authors do recommend referral of OAL patients with gastric symptoms to a gastroenterologist.

Efficacy of eradication therapy in Helicobacter pylori-negative gastric mucosa-associated lymphoid tissue lymphoma: A meta-analysis

BACKGROUND AND AIMS

The role of eradication therapy in Helicobacter pylori-negative gastric mucosa-associated lymphoid tissue (MALT) lymphoma remains controversial. The aim of this study was to investigate the efficacy of H. pylori eradication therapy as a first-line treatment for H. pylori-negative gastric MALT lymphoma.

METHODS

A literature search of studies published until October 2019 was performed using electronic databases. Studies that reported treatment response to eradication therapy as an initial treatment for patients with H. pylori-negative gastric MALT lymphoma were eligible for inclusion. The primary outcome was the complete remission rate after eradication therapy.

RESULTS

Twenty-five studies were included in the analyses. The overall pooled complete remission rate was 29.3% (95% confidence interval [CI], 22.2%-37.4%, I²  = 41.5%). There was no publication bias, and the sensitivity analyses showed consistent results. The pooled complete remission rates were lower in the subgroups of studies that had a higher incidence of translocation t(11;18)(q21;q21) (19.9%, 95% CI, 11.6%-32.0%), studies that used serological tests to exclude H. pylori infection (27.5%, 95% CI, 20.1%-36.4%), and studies where non-response to eradication therapy was determined at <12 months after treatment (27.0%, 95% CI, 15.5%-42.7%). Meta-regression analysis revealed that the pooled estimate was not significantly different in terms of the characteristics of individual studies.

CONCLUSIONS

Although the complete remission rate after eradication therapy is not high, it can be used as an initial treatment option in a subset of patients with H. pylori-negative gastric MALT lymphoma. Further studies to identify subgroups of patients who may benefit from eradication therapy are needed.

Radiotherapy in Early-stage Gastric MALT: Improved Survival Without Increased Cardiac Death

PURPOSE

Radiotherapy (RT) is an effective treatment for localized gastric mucosa-associated lymphoid tissue (MALT) lymphomas unresponsive to antibiotic therapy; however, irradiating the stomach can result in significant radiation to the heart, a risk factor for cardiac disease. We analyzed the Surveillance, Epidemiology, and End Results database to evaluate outcomes related to cardiac disease among patients treated with RT for stage I gastric MALT.

MATERIALS AND METHODS

We identified adult patients treated between 1993 and 2014. The relationship between treatment modality (RT, chemotherapy, combination, and no treatment) and overall survival (OS), mucosa-associated lymphoid tissue-specific survival (MSS), non-mucosa-associated lymphoid tissue-specific survival (non-MSS), and cardiac-specific survival (CSS) was assessed using the Kaplan-Meier estimator and Cox proportional hazards analyses.

RESULTS

A total of 2996 patients (median follow-up, 5.6 y) were analyzed: 27.5% had received RT alone, 12.1% chemotherapy alone, 3.9% chemoradiotherapy, and 56.5% no/unknown treatment (including antibiotic therapy). Compared with RT alone, patients who received chemotherapy alone exhibited worse OS (hazard ratio [HR]: 1.67; 95% confidence interval [CI]: 1.32-2.10; P<0.001) and MSS (HR: 2.10; 95% CI: 1.36-3.23; P=0.001). Although CSS appeared worse in patients who received chemotherapy (HR: 1.56; 95% CI: 0.92-2.66; P=0.10), it was not statistically significant. When comparing orbital and gastric MALT patients, there was no significant difference in CSS (HR: 0.80; 95% CI: 0.49-1.31; P=0.38).

CONCLUSIONS

RT improved survival among patients with stage I gastric MALT without increasing the risk of cardiac death. Those with gastric MALT exhibited similar CSS to those with orbital MALT. Although we cannot analyze nonfatal cardiac toxicity, these results suggest that, absent antibiotic therapy, RT should remain first-line treatment for early-stage gastric MALT.

Is mucosa-associated lymphoid tissue lymphoma an infectious disease? Role of Helicobacter pylori and eradication antibiotic therapy (Review)

Mucosa-associated lymphoid tissue lymphoma (MALT) is seldom considered a diagnosis hypothesis in symptomatic patients. These lymphomas present as a main risk factor for chronic gastritis due to Helicobacter pylori infection. H. pylori leads to chronic inflammation, producing lymphoid tissue in the stomach mucosa (MALT) possibly leading to malignant transformation. Even though H. pylori remains one of the most important factors in the development of MALT lymphoma, it is not mandatory in the evolution of MALT lymphoma since high-grade lymphomas present a lower prevalence of H. pylori. The prevalence of H. pylori is indirectly proportional with the progression into the gastric wall. Mucosal and submucosal MALT lymphomas have a higher prevalence of the bacteria. However, genetic factors remain a risk factor especially if eradication treatment fails. Even though a low percentage of MALT lymphomas are H. pylori-negative, some respond to antibiotic eradication treatment. This can be explained either by the immunomodulatory effect of antibiotics or by other infectious sources such as Helicobacter heilmannii and Campylobacter jejuni (small bowel lymphoma). Treatment in MALT gastric lymphoma was a breakthrough since it was the first time in oncology where tumours were cured by antibiotic therapy, leading us to wonder if MALT lymphomas are infectious disease or not?

MALT lymphoma: epidemiology, clinical diagnosis and treatment

Primary gastric lymphoma (PGL) represents a rare pathology, which can be easily misdiagnosed because of unspecific symptoms of the digestive tract. Histologically, PGL can vary from indolent marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) to aggressive diffuse large B-cell lymphoma (DLBCL). During the years, clinical trials revealed the important role of Helicobacter pylori (H. pylori) in the pathogenesis of gastric MALT lymphoma. Infection with Helicobacter pylori is an influential promoter of gastric lymphomagenesis initiation. Long-term studies revealed that eradication therapy could regress gastric lymphomas.

Gastrointestinal lymphomas: French Intergroup clinical practice recommendations for diagnosis, treatment and follow-up (SNFGE, FFCD, GERCOR, UNICANCER, SFCD, SFED, SFRO, SFH)

INTRODUCTION

This document is a summary of the French Intergroup guidelines on the management of gastro-intestinal lymphomas, available on the web-site of the French Society of Gastroenterology, SNFGE (www.tncd.org), updated in September 2017.

METHODS

This collaborative work was realised under the auspices of several French medical societies and involved clinicians with specific expertise in the field of gastrointestinal lymphomas, including gastroenterologists, haematologists, pathologists, and radiation oncologist, representing the major French or European clinical trial groups. It summarises their consensus on the management of gastrointestinal lymphomas, based on the recent literature data, previous published guidelines and the expert opinions.

RESULTS

The clinical management, and especially the therapeutic strategies of the gastro-intestinal lymphomas are specific to their histological subtypes and to their locations in the digestive tract, with the particularity of gastric MALT lymphomas which are the most frequent and usually related to gastritis induced by Helicobacter pylori.

CONCLUSION

Lymphomas are much less common than epithelial tumours of gastro-intestinal digestive tract. Their different histological subtypes determine their management and prognosis. Each individual case should be discussed within the expert multidisciplinary team.

Helicobacter pylori management in ASEAN: The Bangkok consensus report

Helicobacter pylori (H. pylori) infection remains to be the major cause of important upper gastrointestinal diseases such as chronic gastritis, peptic ulcer, gastric adenocarcinoma, and mucosa-associated lymphoid tissue lymphoma. H. pylori management in ASEAN: the Bangkok consensus report gathered key opinion leaders for the region to review and evaluate clinical aspects of H. pylori infection and to develop consensus statements, rationales, and grades of recommendation for the management of H. pylori infection in clinical practice in ASEAN countries. This ASEAN Consensus consisted of 34 international experts from 10 ASEAN countries, Japan, Taiwan, and the United States. The meeting mainly focused on four issues: (i) epidemiology and disease association; (ii) diagnostic tests; (iii) management; and (iv) follow-up after eradication. The final results of each workshop were presented for consensus voting by all participants. Statements, rationale, and recommendations were developed from the available current evidence to help clinicians in the diagnosis and treatment of H. pylori and its clinical diseases.

First-line antibiotic therapy in Helicobacter pylori-negative low-grade gastric mucosa-associated lymphoid tissue lymphoma

First-line antibiotic treatment for eradicating Helicobacter pylori (HP) infection is effective in HP-positive low-grade gastric mucosa-associated lymphoid tissue lymphoma (MALToma), but its role in HP-negative cases is uncertain. In this exploratory retrospective study, we assessed the outcome and potential predictive biomarkers for 25 patients with HP-negative localized gastric MALToma who received first-line HP eradication (HPE) therapy. An HP-negative status was defined as negative results on histology, rapid urease test, ¹³C urea breath test, and serology. We observed an antibiotic response (complete remission [CR], number = 8; partial remission, number = 1) in 9 (36.0%) out of 25 patients. A t(11;18)(q21;q21) translocation was detected in 7 (43.8%) of 16 antibiotic-unresponsive cases, but in none of the 9 antibiotic-responsive cases (P = 0.027). Nuclear BCL10 expression was significantly higher in antibiotic-unresponsive tumors than in antibiotic-responsive tumors (14/16 [87.5%] vs. 1/9 [11.1%]; P = 0.001). Nuclear NF-κB expression was also significantly higher in antibiotic-unresponsive tumors than in antibiotic-responsive tumors (12/16 [75.0%] vs. 1/9 [11.1%]; P = 0.004). A substantial portion of patients with HP-negative gastric MALToma responded to first-line HPE. In addition to t(11;18)(q21;q21), BCL10 and NF-κB are useful immunohistochemical biomarkers to predict antibiotic-unresponsive status in this group of tumors.

Microbiota as a mediator of cancer progression and therapy

Complex and intricate circuitries regulate cellular proliferation, survival, and growth, and alterations of this network through genetic and epigenetic events result in aberrant cellular behaviors, often leading to carcinogenesis. Although specific germline mutations have been recognized as cancer inducers, the vast majority of neoplastic changes in humans occur through environmental exposure, lifestyle, and diet. An emerging concept in cancer biology implicates the microbiota as a powerful environmental factor modulating the carcinogenic process. For example, the intestinal microbiota influences cancer development or therapeutic responses through specific activities (immune responses, metabolites, microbial structures, and toxins). The numerous effects of microbiota on carcinogenesis, ranging from promoting, preventing, or even influencing therapeutic outcomes, highlight the complex relationship between the biota and the host. In this review, we discuss the latest findings on this complex microbial interaction with the host and highlight potential mechanisms by which the microbiota mediates such a wide impact on carcinogenesis.

Epidemiology and environmental aspects of marginal zone lymphomas

Marginal zone lymphomas (MZLs) account for between 5% and 17% of all non-Hodgkin's lymphomas. MZLs consist of 3 different subtypes with extranodal being the most commonly reported, representing 50-70% of MZL, followed by splenic (20%) and nodal (10%). Median age at presentation varies between these lymphoma sub-types, ranging between 50 and 69 years, with an overall greater incidence noted in males compared to females. Given the rarity of these lymphomas, epidemiologic data has been sparse, although it has been suggested the aetiology is multi-factorial including ethnicity and geographical factors. Other reported associations include autoimmune disease and infection, with Helicobacter pylori and Campylobacter psittaci, being the most commonly reported pathogens. Larger population studies are required to investigate the role of these environmental factors further as these can direct the future management of these lymphomas, through the use of more effective targeted treatments.

[Gastric Mucosa-associated Lymphoid Tissue Lymphoma Based on Outcome of Domestic Treatment]

Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is associated with Helicobacter pylori infection. H. pylori eradication can be performed as a primary therapy regardless of H. pylori status. In Korea, six articles were published about low-grade gastric MALT lymphoma with H. pylori. Complete regression rate after H. pylori eradication is reported at 74.5% to 94.4%. Radiotherapy results in favorable clinical long-term outcomes in patients with early-stage gastric MALT lymphoma who fail H. pylori eradication therapy and those who are H. pylori negative. Chemotherapy could be reserved for patients with metastatic or high-grade lymphoma. In gastric MALT lymphoma, patients with polypoid type on initial endoscopy had a higher likelihood of recurrence than those with diffuse infiltration or ulceration types. The depth of invasion, location of lesions, and chromosomal abnormality with t(11;18) together are predictive factors for failure to remission by H. pylori eradication.

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.

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

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

Primary lymphomas in the gastrointestinal tract

Primary gastrointestinal (GI) lymphomas are uncommon diseases that can involve the whole GI tract. The etiologies of the disease remain unclear, and potential risk factors include celiac disease, Helicobacter pylori infection, use of immunosuppressive agents, human immunodeficiency virus (HIV) or Epstein-Barr virus (EBV) infection and inflammatory bowel disease, etc. Diffuse large B-cell lymphoma (DLBCL) and mucosa-associated lymphoid tissue (MALT) lymphoma are the most common subtypes of GI lymphomas. B-cell lymphomas of the GI tract are more common in Western countries, while in Asia-Pacific region T-cell lymphomas are more frequently reported. In this review, lymphomas in the esophagus, stomach and intestine are described, including their epidemiology, histology, clinical manifestations, endoscopic findings, radiological features and treatment.

Antibiotic treatment as sole management of Helicobacter pylori-negative gastric MALT lymphoma: a single center experience with prolonged follow-up

Relatively little is known about the long-term outcome of patients with Helicobacter pylori (HP)-negative gastric lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) with antibiotic therapy as sole management. We have analyzed all patients with HP-negative gastric MALT lymphoma undergoing antibiotic therapy as sole management of their disease. HP negativity was defined as negative histology, breath test and serology, and response to treatment, survival and long-term outcome was assessed together with clinico-pathological characteristics including t(11; 18) (q21; q21) translocation. Out of 97 patients with gastric MALT lymphoma, 24 were HP-negative, and 13 (5 females and 8 males) underwent only antibiotic management for initial therapy. Eight had stage I and five were found to have stage II disease, with three patients suffering from an underlying autoimmune disease. Antibiotic therapy consisted of standard HP eradication regimens consisting of clarithromycin in all patients, along with metronidazole in seven and amoxicillin in six plus a proton-pump inhibitor. After a median follow-up of 95 months (42-, 181+), 12/13 patients are alive. Six patients with stage I disease achieved an objective response (five complete (CR) and one partial remission, 46 %), four had stable disease (lasting 11-27 months), and three progressed. All patients with stable disease received chemotherapy, but only one patient due to clear cut progression. One patient relapsed 23 months after initial CR, and achieved a second CR with antibiotics now lasting 87 months. These results indicate that a relevant percentage of patients with HP-negative gastric MALT lymphoma may benefit from antibiotic therapy and do not require additional oncological therapies. Our data suggest that the remissions seen in these patients might be durable as evidenced by prolonged follow-up in our series.

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.

[Guidelines for the diagnosis and treatment of Helicobacter pylori infection in Korea, 2013 revised edition]

Since the Korean College of Helicobacter and Upper Gastrointestinal Research has first developed the guideline for the diagnosis and treatment of Helicobacter pylori infection in 1998, the revised guideline was proposed in 2009 by the same group. Although the revised guideline was made by comprehensive review of previous articles and consensus of authoritative expert opinions, the evidence-based developmental process was not applied in the revision of the guideline. This new guideline has been revised especially in terms of changes in the indication and treatment of H. pylori infection in Korea, and developed by the adaptation process as evidence-based method; 6 guidelines were retrieved by systematic review and the Appraisal of Guidelines for Research and Evaluation (AGREE) II process, 21 statements were made with grading system and revised by modified Delphi method. After revision, 11 statements for the indication of test and treatment, 4 statements for the diagnosis and 4 statements for the treatment have been developed, respectively. The revised guideline has been reviewed by external experts before the official endorsement, and will be disseminated for usual clinical practice in Korea. Also, the scheduled update and revision of the guideline will be made periodically.

Guidelines for the diagnosis and treatment of Helicobacter pylori infection in Korea, 2013 revised edition

The Korean College of Helicobacter and Upper Gastrointestinal Research first developed guidelines for the diagnosis and treatment of Helicobacter pylori (H. pylori) infection in 1998, and revised guidelines were proposed in 2009 by the same group. Although the revised guidelines were based on a comprehensive review of published articles and the consensus of expert opinions, the revised guidelines were not developed using an evidence-based process. The new guidelines presented in this study include specific changes regarding indication and treatment of H. pylori infection in Korea, and were developed through the adaptation process using an evidence-based approach. After systematic review of the literature, six guidelines were selected using the Appraisal of Guidelines for Research and Evaluation (AGREE) II process. A total of 21 statements were proposed with the grading system and revised using the modified Delphi method. After the guideline revisions, 11 statements about indication of test and treatment, four statements about diagnosis, and four statements about treatment of H. pylori infection were developed. The revised guidelines were reviewed by external experts before receiving official endorsement from the Korean College of Helicobacter and Upper Gastrointestinal Research, and disseminated to physicians and other medical professionals for use in clinical practice in Korea. The guidelines will continue to be updated and revised periodically.

Detection of genotypic clarithromycin-resistant Helicobacter pylori by string tests

AIM

To evaluate the utility of the string test to detect genotypic clarithromycin-resistant Helicobacter pylori (H. pylori) by polymerase chain reaction (PCR)-restriction fragment length polymorphism.

METHODS

Patients undergoing endoscopic examinations were enrolled in the present study. String tests were done on the next day of endoscopy. Segments of 23S rRNA were amplified from DNA obtained from string tests. PCR-restriction fragment length polymorphism was accomplished by restriction enzymes BbsI and BsaI recognizing the mutation site A to G at 2143 or at 2142 of 23S rRNA domain V, respectively.

RESULTS

One hundred and thirty-four patients with H. pylori infection underwent string tests. To compare phenotypic resistance, 43 isolates were successfully cultured in 79 patients in whom 23S rRNA was successfully amplified. Of five patients with clarithromycin-resistant H. pylori, 23S rRNA of H. pylori isolates from four patients could be digested by BsaI. In 38 susceptible isolates, 23S rRNA of H. pylori isolates from 36 patients could not be digested by either BsaI or BbsI. The sensitivity and specificity of the string test to detect genotypic clarithromycin resistance were 66.7% and 97.3%, respectively. Positive and negative predictive values were 80% and 94.7%, respectively.

CONCLUSION

String test with molecular analysis is a less invasive method to detect genotypic resistance before treatment. Further large-scale investigations are necessary to confirm our results.

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

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

Gastric MALT lymphoma: old and new insights

The stomach is the most frequent site of extranodal lymphoma. Gastric lymphoma originating from mucosa-associated lymphoid tissue (MALT) is typically a low-grade, B-cell neoplasia strongly associated with Helicobacter pylori (H. pylori) infection. Only certain H. pylori strains in some predisposed patients determine lymphoma development in the stomach, according to a strain-host-organ specific process. The clinical presentation is poorly specific, symptoms ranging from vague dyspepsia to alarm symptoms. Similarly, different endoscopy patterns have been described for gastric lymphoma. H. pylori eradication is advised as first-line therapy in early stage disease, and complete lymphoma remission is achieved in 75% of cases. Neoplasia stage, depth of infiltration in the gastric wall, presence of the API2-MALT1 translocation, localization in the stomach, and patient ethnicity have been identified as predictors of remission. Recent data suggests that H. pylori eradication therapy may be successful for gastric lymphoma treatment also in a small subgroup (15%) of H. pylori-negative patients. The overall 5-year survival and disease-free survival rates are as high as 90% and 75%, respectively. Management of patients who failed to achieve lymphoma remission following H. pylori eradication include radiotherapy, chemotherapy and, in selected cases, surgery.

A case of Helicobactor pylori negative low-grade gastric MALT lymphoma in an elderly female, successfully treated with rituximab

PATIENT

Female, 91 FINAL DIAGNOSIS: Low-grade gastric MALT lymphoma Symptoms: Recurrent epigastric and right upper quadrant dyscomfort Medication: Rituximab Clinical Procedure: esophagogastroduodenoscopy • gastric biopsy Specialty: Gastroenterology.

OBJECTIVE

Unusual or unexpected effect of treatment.

BACKGROUND

Mucosa associated lymphoid tissue (MALT) lymphoma can occur in any extranodal organ or tissue, stomach being the common site. Most of the gastric MALT lymphomas are related to chronic H. pylori infection. H. pylori negative gastric MALT lymphoma is relatively uncommon and usually treated with a short course of chemotherapy, radiotherapy or surgery.

CASE REPORT

Herein, we present a case of an elderly female with H. pylori negative, low-grade gastric MALT lymphoma that was successfully treated with a short course of rituximab.

CONCLUSIONS

This case report emphasizes that rituximab monotherapy can be an effective treatment for H. pylori negative low grade gastric MALT lymphoma especially in an elderly patient where surgery or radiotherapy may not be appropriate.

Clinical outcomes of radiation therapy for early-stage gastric mucosa-associated lymphoid tissue lymphoma

AIM: To evaluate the clinical outcomes of radiation therapy (RT) for early-stage gastric mucosa-associated lymphoid tissue lymphoma (MALToma).

METHODS: The records of 64 patients treated between 1998 and 2011 were analyzed retrospectively. For Helicobacter pylori (H. pylori)-positive patients (n = 31), chemotherapy or H. pylori eradication therapy was the initial treatment. In patients with failure after H. pylori eradication, RT was performed. For H. pylori-negative patients (n = 33), chemotherapy or RT was the first-line treatment. The median RT dose was 36 Gy. The target volume included the entire stomach and the perigastric lymph node area.

RESULTS: All of the patients completed RT without interruption and showed complete remission on endoscopic biopsy after treatment. Over a median follow-up period of 39 mo, the 5-year local control rate was 89%. Salvage therapy was successful in all relapsed patients. Secondary malignancies developed in three patients. The 5-year overall survival rate was 94%. No patient presented symptoms of moderate-to-severe treatment-related toxicities during or after RT.

CONCLUSION: Radiotherapy results in favorable clinical outcomes in patients with early-stage gastric MALToma who experience failure of H. pylori eradication therapy and those who are H. pylori negative.

A retrospective study of 5-year outcomes of radiotherapy for gastric mucosa-associated lymphoid tissue lymphoma refractory to Helicobacter pylori eradication therapy

BACKGROUND

The favorable response rate of radiotherapy for localized gastric mucosa-associated lymphoid tissue lymphoma refractory to Helicobacter pylori eradication has been demonstrated. However, there are limited data available on the long-term outcomes. The aim of this retrospective study was to evaluate the long-term outcomes of radiotherapy for localized gastric mucosa-associated lymphoid tissue lymphoma refractory to Helicobacter pylori eradication.

METHODS

Thirty-four consecutive patients with localized gastric mucosa-associated lymphoid tissue lymphoma that were refractory to eradication were treated with radiotherapy (a total dose of 30 Gy). The response and adverse events of radiotherapy were retrospectively analyzed as short-term outcomes, and recurrence-free, overall and disease-specific survival rates were calculated as long-term outcomes.

RESULTS

Thirty-three (97.1%) patients achieved complete remission and radiotherapy was well tolerated. One patient underwent emergency gastrectomy due to severe hematemesis. Of the 34 patients during the median follow-up period of 7.5 (1.2-13.0) years, one patient had local recurrence after 8.8 years, one patient underwent surgery for bowel obstruction secondary to small bowel metastasis after 5.1 years and one patient had pulmonary metastasis after 10.9 years. Pathologically, all three recurrences revealed mucosa-associated lymphoid tissue lymphoma without any transformation to high-grade lymphoma. None died of gastric mucosa-associated lymphoid tissue lymphoma. The 5-year recurrence-free survival rate was 97.0%. The 5-year overall survival rates and disease-specific survival rates were 97.0 and 100%, respectively.

CONCLUSIONS

Radiotherapy in patients with localized gastric mucosa-associated lymphoid tissue lymphoma refractory to Helicobacter pylori eradication can achieve excellent overall survival. However, long-term surveillance is necessary to identify late recurrences.

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

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

Association of the virulence factors of Helicobacter pylori and gastric mucosal interleukin-17/23 mRNA expression in dyspeptic patients

The molecular pathways that control Helicobacter pylori (Hp)-associated inflammatory reaction are complex, but locally induced cytokines and virulence factors seem to have a major role in maintaining the ongoing inflammation. Therefore this study was aimed to evaluate the association of the virulence factors of Hp and gastric mucosal interleukin-17/23 mRNA expression in dyspeptic patients. Mucosal IL-17 and IL-23 mRNA expression in H. pylori infected and non-infected gastric biopsies were determined by real-time RT-PCR. Virulence factors, vac-A and cag-A were evaluated using PCR. There was no significant difference in mucosal IL-17 and IL-23 mRNA expression between H. pylori infected and non-infected patients. Their expression in mucosa did not correlate with chronic gastritis and chronic active gastritis. IL-17 and IL-23 mRNA expression in mucosa of patients with vacA m1 were significantly higher than those observed in patients with vacA m2. The severity of polymorphonuclear infiltration and chronic active gastritis was higher in cag-A positive than cag-A negative patients. H. pylori infections carrying the vacA m1 allele have higher IL-17 and IL-23 mRNA and the current study suggests that the virulence factor vacA allele's m1 are important for the severe gastric inflammation.

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.

Primary gastrointestinal lymphoma

Gastrointestinal tract is the most common extranodal site involved by lymphoma with the majority being non-Hodgkin type. Although lymphoma can involve any part of the gastrointestinal tract, the most frequent sites in order of its occurrence are the stomach followed by small intestine and ileocecal region. Gastrointestinal tract lymphoma is usually secondary to the widespread nodal diseases and primary gastrointestinal tract lymphoma is relatively rare. Gastrointestinal lymphomas are usually not clinically specific and indistinguishable from other benign and malignant conditions. Diffuse large B-cell lymphoma is the most common pathological type of gastrointestinal lymphoma in essentially all sites of the gastrointestinal tract, although recently the frequency of other forms has also increased in certain regions of the world. Although some radiological features such as bulky lymph nodes and maintenance of fat plane are more suggestive of lymphoma, they are not specific, thus mandating histopathological analysis for its definitive diagnosis. There has been a tremendous leap in the diagnosis, staging and management of gastrointestinal lymphoma in the last two decades attributed to a better insight into its etiology and molecular aspect as well as the knowledge about its critical signaling pathways.