Helicobacter pylori Eradication Therapy Is Effective as the Initial Treatment for Patients with H. pylori-Negative and Disseminated Gastric Mucosa-Associated Lymphoid Tissue Lymphoma

Response-adapted ultra-low-dose 4 Gy radiation as definitive therapy of gastric MALT lymphoma: a single-centre, pilot trial

BACKGROUND

Given the favourable prognosis of patients with gastric mucosa-associated lymphoid tissue (MALT) lymphoma, treatment-related toxicity should be minimised. We aimed to evaluate the efficacy of 4 Gy radiotherapy given in a response-adapted approach.

METHODS

We conducted a single-centre, single-arm, prospective trial at MD Anderson Cancer Center (Houston, TX, USA) of response-adapted ultra-low-dose radiotherapy. Eligible patients were 18 years or older and had newly diagnosed or relapsed Helicobacter pylori-negative gastric MALT lymphoma, with stage I-IV disease. Given the expected low toxicity profile of treatment, performance status was not an exclusion criterion. Patients received external beam photon-based radiotherapy for a total dose of 4 Gy in two fractions. Patients with a complete response to 4 Gy via endoscopy and imaging at 3-4 months were observed; patients with a partial response were re-evaluated in 6-9 months. Residual disease at 9-13 months or stable or progressive disease at any time required additional treatment with 20 Gy. The primary endpoint was gastric complete response at 1 year (second evaluation timepoint) after 4 Gy treatment. All analyses were performed as intention to treat. This trial is registered at ClinicalTrials.gov (NCT03680586) and is complete and closed to enrolment.

FINDINGS

Between March 27, 2019, and Oct 12, 2021, we enrolled 24 eligible patients. The median age of participants was 67 years (IQR 58-74; range 40-85); 15 (63%) were female and nine (37%) male; 18 (75%) were White, four (17%) Asian, and two (8%) Hispanic; 20 (83%) had stage I disease, one (4%) stage II, and three (13%) stage IV. Median follow-up time was 36 months (IQR 26-42). 20 patients (83%) had a complete response to 4 Gy (16 at 3-4 months, four at 9-13 months); two patients received 20 Gy for symptomatic stable disease at 3-4 months and two for residual disease at 9-13 months; all had a complete response. The 3-year local control rate was 96% (95% CI 88-100), with one local relapse at 14 months after 4 Gy radiotherapy salvaged successfully with 20 Gy. One patient with stage IV disease had a distant relapse. The most common adverse events were grade 1 nausea (nine [38%] of 24 patients who received 4 Gy and two [50%] of four patients who received 20 Gy) and grade 1 abdominal pain (five [21%] of 24 and zero of four, respectively). No grade 3 or worse adverse events were noted, including no treatment-related deaths.

INTERPRETATION

Most patients had a complete response after 4 Gy radiotherapy; all who required an additional 20 Gy had a complete response within 12 months. This response-adapted strategy could be used to select patients who would benefit from additional radiotherapy and spare others potential associated toxicity.

FUNDING

National Cancer Institute.

Should All Patients With Stage IE Gastric Mucosa-Associated Lymphoid Tissue Lymphoma Receive Antibiotic Eradication Therapy for Helicobacter pylori?

PURPOSE

H. pylori eradication therapy (HPE) can lead to tumor regression in H. pylori-positive (HPP) gastric mucosa-associated lymphoid tissue (MALT) lymphoma. However, some patients do not have detectable H. pylori (HP) infection (H. pylori-negative [HPN]) and the guidelines differ in their initial approach to HPN patients. The National Comprehensive Cancer Network (NCCN) recommends proceeding to radiation therapy, whereas European Society for Medical Oncology suggests HPE for every patient, even those who are HPN. To address this issue, we evaluated the effectiveness of HPE in limited-stage gastric MALT lymphoma.

MATERIALS AND METHODS

We retrospectively reviewed patients newly diagnosed with stage IE gastric MALT lymphoma between January 2002 and December 2022. The primary outcome was the complete remission (CR) rate defined as no macroscopic findings of lymphoma and negative gastric biopsy at the follow-up gastric endoscopy.

RESULTS

Fifty-two patients were reviewed, and HP infection was detected in 19 (36.5%) patients-14 by immunostaining, three by serology, and one each by stool antigen and urea breath test. All 19 HPP and eight of the 33 HPN patients received HPE treatment. The CR rate was 63% (12/19) in HPP patients and 13% (1/8) in HPN patients (P = .033). After a median follow-up of 89.7 months, only two of the 12 HPP patients achieving CR have relapsed; the one HPN patient who received HPE remains in CR at 12+ months.

CONCLUSION

For limited-stage HPP gastric MALT lymphoma, HPE is an effective and durable first-line treatment and should be used. For HPN patients, the CR rate with HPE is very low in our experience and is thus in support of the NCCN guideline.

Helicobacter pylori and Gastrointestinal Cancers: Recent Advances and Controversies

Helicobacter pylori (H pylori), a gastric bacterium, has been extensively studied for its association with gastritis, peptic ulcers, and gastric cancer. However, recent evidence suggests its potential implications beyond the stomach, linking it to other gastrointestinal malignancies, such as esophageal cancer, liver cancer, pancreatic cancer, gallbladder cancer, and colorectal cancer. In light of the expanding research landscape and the increasing interest in exploring H pylori broader role in gastrointestinal tumorigenesis, this comprehensive review aims to elucidate the relationship between H pylori and gastrointestinal tumors. This review encompasses recent epidemiological studies, research progress, and emerging perspectives, providing a comprehensive assessment of the relationship between H pylori and gastrointestinal tumors. The findings highlight the captivating world of H pylori and its intricate involvement in gastrointestinal malignancies.

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.

Practice guidelines for the management of Helicobacter pylori infection: The Saudi H. pylori Working Group recommendations

The eradication rates for Helicobacter pylori globally are decreasing with a dramatic increase in the prevalence of antibiotic resistant bacteria all over the world, including Saudi Arabia. There is no current consensus on the management of H. pylori in Saudi Arabia. The Saudi Gastroenterology Association developed these practice guidelines after reviewing the local and regional studies on the management of H. pylori. The aim was to establish recommendations to guide healthcare providers in managing H. pylori in Saudi Arabia. Experts in the areas of H. pylori management and microbiology were invited to write these guidelines. A literature search was performed, and all authors participated in writing and reviewing the guidelines. In addition, international guidelines and consensus reports were reviewed to bridge the gap in knowledge when local and regional data were unavailable. There is limited local data on treatment of H. pylori. The rate of clarithromycin and metronidazole resistance is high; therefore, standard triple therapy for 10-14 days is no longer recommended in the treatment of H. pylori unless antimicrobial susceptibility testing was performed. Based on the available data, bismuth quadruple therapy for 10-14 days is considered the best first-line and second-line therapy. Culture and antimicrobial susceptibility testing should be considered following two treatment failures. These recommendations are intended to provide the most relevant evidence-based guidelines for the management of H. pylori infection in Saudi Arabia. The working group recommends further studies to explore more therapeutic options to eradicate H. pylori.

Targeted delivery of a short antimicrobial peptide (CM11) against Helicobacter pylori gastric infection using concanavalin A-coated chitosan nanoparticles

Helicobacter pylori is the cause of most cases of stomach ulcers and also causes some digestive cancers. The emergence and spread of antibiotic-resistant strains of H. pylori is one of the most important challenges in the treatment of its infections. The present study aims to develop a concanavalin A (ConA) coated chitosan (CS) nanocarrier-based drug delivery for the targeted release of peptides to the site of H. pylori infection. Accordingly, chitosan was used as an encapsulating agent for CM11 peptide delivery by applying ionotropic gelation method. Con-A was used for coating CS nanoparticles to target H. pylori. The CS NPs and ConA-CS NPs were characterized by FTIR, dynamic light scattering (DLS), and scanning electron microscopy (SEM). The MIC of CM11-loaded ConA-CS NPs against H. pylori SS1 strain was analyzed in vitro. In order to evaluate the treatment efficiency in vivo, a gastric infection model of H. pylori SS1 strain was established in mice and histopathological studies and IL-1β cytokine assay were performed. Based on the results, the size frequency for CS NPs and ConA-CS NPs was about 200 and 350 nm, respectively. The prepared CM11-loaded ConA-CS NPs exhibited antibacterial activity against H. pylori SS1 strain with a concentration of 32 µg/ml. The highest healing process was observed in synthesized CM11-loaded ConA-CS NPs treatments and a significant decrease in IL-1β was observed. Our findings highlight the potential of chitosan nanoparticles as a drug delivery vehicle in the treatment of gastric infection model of H. pylori SS1 strain.

Endoscopic and Histopathological Characteristics of Gastrointestinal Lymphoma: A Multicentric Study

Background: Extranodal non-Hodgkin lymphoma (NHL) is more prevalent in the gastrointestinal (GI) tract than in other sites. This study aimed to determine the endoscopic characteristics of primary gastrointestinal non-Hodgkin lymphomas. Methods: We investigated 140 patients from three tertiary referral hospitals with primary malignant lymphoma of the gastrointestinal tract. Characteristics of the lesions were evaluated and analyzed using image-enhanced endoscopy, endoscopic ultrasound, and histopathology. Results: The median age was 60.5 (range: 11-99), and 59 (42.1%) were female. The most frequent complaint was abdominal pain (74.3%), followed by bloody feces (10%) and diarrhea (2.9%). B symptoms were observed in 15 (10.7%) patients. GI obstruction was the most common complication (10.0%), followed by hemorrhage (7.9%) and perforation (1.5%). Regarding endoscopic findings, the identified sites were the following: the stomach (61.4%), colon (10%), small intestine (10%), ileocecum (8.6%), rectum (6.4%), and duodenum (3.6%). Diffuse large B-cell lymphoma (DLBCL) and mucosa-associated lymphoid tissue (MALT) lymphoma are most prevalent in the stomach. Helicobacter pylori was identified in 46 cases (39.0%), with MALT lymphoma being the most infected subtype. Nearly all gastrointestinal non-Hodgkin lymphomas manifested as superficial type (25-59.6%) and ulcer type (15.6-50%) under endoscopy. We found that fungating type and protruding with ulcer type were more frequent types of aggressive lymphomas (diffuse large B-cell lymphoma, mantle cell lymphoma, and T-cell lymphoma) compared to the indolent types (MALT lymphoma, follicular lymphoma, duodenal-type follicular lymphoma, and small lymphocytic lymphoma) (p < 0.05). Conclusions: This study showed that most subtypes of gastrointestinal non-Hodgkin lymphomas exhibited same endoscopic features (superficial type and ulcer type). Aggressive gastrointestinal non-Hodgkin lymphomas (diffuse large B-cell lymphoma, mantle cell lymphoma, and T-cell lymphoma) were highly suspected when fungating lesions and protruding with ulcer lesions were encountered under endoscopy. Endoscopists should be aware of the connection between enhanced endoscopic characteristics and histological varieties of gastrointestinal lymphoma to improve diagnosis.

An Overview of Selected Bacterial Infections in Cancer, Their Virulence Factors, and Some Aspects of Infection Management

In cancer development and its clinical course, bacteria can be involved in etiology and secondary infection. Regarding etiology, various epidemiological studies have revealed that Helicobacter pylori can directly impact gastric carcinogenesis. The Helicobacter pylori-associated virulence factor cytotoxin-associated gene A perhaps plays an important role through different mechanisms such as aberrant DNA methylation, activation of nuclear factor kappa B, and modulation of the Wnt/β-catenin signaling pathway. Many other bacteria, including Salmonella and Pseudomonas, can also affect Wnt/β-catenin signaling. Although Helicobacter pylori is involved in both gastric adenocarcinoma and mucosa-associated lymphoid tissue lymphoma, its role in the latter disease is more complicated. Among other bacterial species, Chlamydia is linked with a diverse range of diseases including cancers of different sites. The cellular organizations of Chlamydia are highly complex. Interestingly, Escherichia coli is believed to be associated with colon cancer development. Microorganisms such as Escherichia coli and Pseudomonas aeruginosa are frequently isolated from secondary infections in cancer patients. In these patients, the common sites of infection are the respiratory, gastrointestinal, and urinary tracts. There is an alarming rise in infections with multidrug-resistant bacteria and the scarcity of suitable antimicrobial agents adversely influences prognosis. Therefore, effective implementation of antimicrobial stewardship strategies is important in cancer patients.

Signaling pathways of oxidative stress response: the potential therapeutic targets in gastric cancer

Gastric cancer is one of the top causes of cancer-related death globally. Although novel treatment strategies have been developed, attempts to eradicate gastric cancer have been proven insufficient. Oxidative stress is continually produced and continually present in the human body. Increasing evidences show that oxidative stress contributes significantly to the development of gastric cancer, either through initiation, promotion, and progression of cancer cells or causing cell death. As a result, the purpose of this article is to review the role of oxidative stress response and the subsequent signaling pathways as well as potential oxidative stress-related therapeutic targets in gastric cancer. Understanding the pathophysiology of gastric cancer and developing new therapies for gastric cancer depends on more researches focusing on the potential contributors to oxidative stress and gastric carcinogenesis.

Synchronous early gastric and intestinal mucosa-associated lymphoid tissue lymphoma in a Helicobacter pylori-negative patient: A case report

BACKGROUND

Mucosa-associated lymphoid tissue (MALT) lymphoma occurs largely in the digestive tract, with the stomach being the most commonly affected organ, followed by the small intestine, large intestine, and esophagus. It is rarely found in both the stomach and colon. Helicobacter pylori (H. pylori) infection is strongly associated with gastric MALT lymphoma, although there is a small number of H. pylori-negative gastric MALT lymphomas. Diagnosis of MALT lymphoma is challenging because of nonspecific symptoms and diverse presentations of endoscopic findings.

CASE SUMMARY

We report a case of an asymptomatic patient who during screening endoscopy and was found to have stromal tumor-like submucosal uplift lesions in the stomach body and polypoid lesions in the rectum. After endoscopic resection, the patient was diagnosed with multiple early simultaneous gastrointestinal MALT lymphomas.

CONCLUSION

This study may help improve our understanding of MALT lymphomas and multifocal lesions treated using early endoscopy.

Bacteria-Mediated Oncogenesis and the Underlying Molecular Intricacies: What We Know So Far

Cancers are known to have multifactorial etiology. Certain bacteria and viruses are proven carcinogens. Lately, there has been in-depth research investigating carcinogenic capabilities of some bacteria. Reports indicate that chronic inflammation and harmful bacterial metabolites to be strong promoters of neoplasticity. Helicobacter pylori-induced gastric adenocarcinoma is the best illustration of the chronic inflammation paradigm of oncogenesis. Chronic inflammation, which produces excessive reactive oxygen species (ROS) is hypothesized to cause cancerous cell proliferation. Other possible bacteria-dependent mechanisms and virulence factors have also been suspected of playing a vital role in the bacteria-induced-cancer(s). Numerous attempts have been made to explore and establish the possible relationship between the two. With the growing concerns on anti-microbial resistance and over-dependence of mankind on antibiotics to treat bacterial infections, it must be deemed critical to understand and identify carcinogenic bacteria, to establish their role in causing cancer.

Helicobacter pylori-Mediated Oxidative Stress and Gastric Diseases: A Review

Gastric cancer is considered to be a type of gastrointestinal tumor and is mostly accompanied by Helicobacter pylori (HP) infection at the early stage. Hence, the long-term colonization of the gastric mucosa by HP as a causative factor for gastrointestinal diseases cannot be ignored. The virulence factors secreted by the bacterium activate the signaling pathway of oxidative stress and mediate chronic inflammatory response in the host cells. The virulence factors also thwart the antibacterial effect of neutrophils. Subsequently, DNA methylation is induced, which causes continuous cell proliferation and evolution toward low-grade-differentiated gastric cells. This process provides the pathological basis for the occurrence of progressive gastric cancer. Therefore, this review aims to summarize the oxidative stress response triggered by HP in the gastric mucosa and the subsequent signaling pathways. The findings are expected to help in the formulation of new targeted drugs for preventing the occurrence of early gastric cancer and its progression to middle and advanced cancer.

Current Status of the Spectrum and Therapeutics of Helicobacter pylori-Negative Mucosa-Associated Lymphoid Tissue Lymphoma

Simple Summary

The prevalence of Helicobacter pylori (HP)-negative gastric mucosa-associated lymphoid tissue (MALT) lymphoma has increased over the last two decades, whereas that of HP-positive gastric MALT lymphoma has decreased. Although the role of first-line antibiotics in the treatment of HP-negative gastric MALT lymphomas remains ambiguous, several case series have reported that a first-line HP eradication therapy (HPE)-like regimen could result in complete remission in a proportion of patients with localized HP-negative gastric MALT lymphoma. Previous sporadic reports have indicated that certain patients with extragastric MALT lymphoma can respond to first-line antibiotic treatment as well. These findings suggest that, in contrast to antibiotic-unresponsive tumors, antibiotic-responsive tumors may be recognized within the spectrum of HP-negative MALT lymphoma. In addition to conventional chemotherapy and immunochemotherapy, macrolide antibiotics and immunomodulatory drugs have been previously used and demonstrated to be efficacious. This article provides the spectrum and therapeutics for HP-negative MALT lymphoma.

Abstract

Helicobacter pylori (HP)-unrelated mucosa-associated lymphoid tissue (MALT) lymphoma includes the majority of extragastric MALT lymphomas and a small proportion of gastric MALT lymphomas. Although the role of first-line antibiotics in treating HP-negative gastric MALT lymphomas remains controversial, HP eradication therapy (HPE)-like regimens may result in approximately 20–30% complete remission (CR) for patients with localized HP-negative gastric MALT lymphoma. In these patients, H. heilmannii, H. bizzozeronii, and H. suis were detected in sporadic gastric biopsy specimens. Extragastric MALT lymphoma is conventionally treated with radiotherapy for localized disease and systemic chemotherapy for advanced and metastatic diseases. However, a proportion of extragastric MALT lymphomas, such as ocular adnexal lesions and small intestinal lesions, were reported to be controlled by antibiotics for Chlamydophila psittaci and Campylobacter jejuni, respectively. Some extragastric MALT lymphomas may even respond to first-line HPE. These findings suggest that some antibiotic-responsive tumors may exist in the family of HP-negative MALT lymphomas. Two mechanisms underlying the antibiotic responsiveness of HP-negative MALT lymphoma have been proposed. First, an HPE-like regimen may eradicate the antigens of unknown bacteria. Second, clarithromycin (the main component of HPE) may have direct or indirect antineoplastic effects, thus contributing to the CR of these tumors. For antibiotic-unresponsive HP-negative MALT lymphoma, high-dose macrolides and immunomodulatory drugs, such as thalidomide and lenalidomide, have reported sporadic success. Further investigation of new treatment regimens is warranted.

Mucosa-Associated Lymphoid Tissue (MALT) Lymphoma in the Gastrointestinal Tract in the Modern Era

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) typically arises from sites such as the stomach, where there is no organized lymphoid tissue. Close associations between Helicobacter pylori and gastric MALT lymphoma or Campylobacter jejuni and immunoproliferative small intestinal disease (IPSID) have been established. A subset of tumors is associated with chromosomal rearrangement and/or genetic alterations. This disease often presents as localized disease, requiring diverse treatment approaches, from antibiotic therapy to radiotherapy and immunochemotherapy. Eradication therapy for H. pylori effectively cures gastric MALT lymphoma in most patients. However, treatment strategies for H. pylori-negative gastric MALT lymphoma are still challenging. In addition, the effectiveness of antibiotic therapy has been controversial in intestinal MALT lymphoma, except for IPSID. Endoscopic treatment has been noted to usually achieve complete remission in endoscopically resectable colorectal MALT lymphoma with localized disease. MALT lymphoma has been excluded from post-transplant lymphoproliferative disorders with the exception of Epstein–Barr virus (EBV)-positive marginal zone lymphoma (MZL). We also describe the expanding spectrum of EBV-negative MZL and a close association of the disease with the gastrointestinal tract.

What you always wanted to know about gastric MALT-lymphoma: a focus on recent developments

The stomach is the most common site of origin for extranodal lymphomas, with extranodal marginal zone B-cell of the mucosa associated lymphoid tissue (MALT-lymphoma) being the predominant subtype. MALT-lymphoma develops in mucosa associated lymphoid structures acquired by infection or chronic antigenic stimuli and may therefore arise in almost any organ of the human body. In spite of histopathologic similarities between various organs upon first glance, recent findings suggest pronounced differences between different sites, with a variety of features specific to gastric MALT-lymphoma. The objective of this review is to sum up the current knowledge on pathogenesis, molecular pathology, clinical presentation and therapeutic approaches to gastric MALT-lymphoma with in-depth discussion of recent developments.

Helicobacter pylori Infection

Helicobacter pylori infection remains one of the most prevalent infections worldwide, causing significant morbidity and mortality from gastric malignancies and peptic ulcers. This article provides a summary of the microbiology and pathogenesis of this bacterium, emphasizing the complex and protean effects of H pylori on gastric epithelial cells, including stem and progenitor populations, and evasion of host immune defenses. Increasing antibiotic resistance has made management more challenging. This article discusses the appropriate diagnostic modality for different clinical scenarios, and the evolving treatment of H pylori infections, including the use of antibiotic susceptibility testing to aid regimen selection.

Efficacy of Helicobacter pylori eradication therapy for treatment of functional dyspepsia: A protocol for systematic review and meta-analysis

OBJECTIVE

The effect of Helicobacter pylori (H pylori) eradication therapy in functional dyspepsia (FD) patients was inconsistent in previously published randomized controlled trials. Therefore, we performed a comprehensive protocol for systematic review and meta-analysis in order to assess whether H pylori eradication therapy benefits patients with FD.

METHODS

In this systematic review and meta-analysis, we will search Web of Science, Embase, PubMed, Wanfang Data, Medline, Science Direct, Cochrane Library through April, 2021. The protocol was written following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols. Data extraction was performed independently and only randomized clinical trials were included in this study. The risk of bias assessment was performed using the tool recommended in the Cochrane Handbook for Systematic Reviews of Interventions. All calculations were carried out with Stata 11.0 (The Cochrane Collaboration, Oxford, United Kingdom).

RESULTS

We hypothesized that H pylori eradication therapy compared to no eradication therapy has a statistically significant benefit for symptom relief and can also reduce the development of peptic ulcer disease.

CONCLUSION

This study expects to provide credible and scientific evidence for the efficacy of H pylori eradication therapy for patients with FD.

OSF REGISTRATION NUMBER

10.17605/OSF.IO/4EHRB.

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.

Pathways of Gastric Carcinogenesis, Helicobacter pylori Virulence and Interactions with Antioxidant Systems, Vitamin C and Phytochemicals

Helicobacter pylori is a class one carcinogen which causes chronic atrophic gastritis, gastric intestinal metaplasia, dysplasia and adenocarcinoma. The mechanisms by which H. pylori interacts with other risk and protective factors, particularly vitamin C in gastric carcinogenesis are complex. Gastric carcinogenesis includes metabolic, environmental, epigenetic, genomic, infective, inflammatory and oncogenic pathways. The molecular classification of gastric cancer subtypes has revolutionized the understanding of gastric carcinogenesis. This includes the tumour microenvironment, germline mutations, and the role of Helicobacter pylori bacteria, Epstein Barr virus and epigenetics in somatic mutations. There is evidence that ascorbic acid, phytochemicals and endogenous antioxidant systems can modify the risk of gastric cancer. Gastric juice ascorbate levels depend on dietary intake of ascorbic acid but can also be decreased by H. pylori infection, H. pylori CagA secretion, tobacco smoking, achlorhydria and chronic atrophic gastritis. Ascorbic acid may be protective against gastric cancer by its antioxidant effect in gastric cytoprotection, regenerating active vitamin E and glutathione, inhibiting endogenous N-nitrosation, reducing toxic effects of ingested nitrosodimethylamines and heterocyclic amines, and preventing H. pylori infection. The effectiveness of such cytoprotection is related to H. pylori strain virulence, particularly CagA expression. The role of vitamin C in epigenetic reprogramming in gastric cancer is still evolving. Other factors in conjunction with vitamin C also play a role in gastric carcinogenesis. Eradication of H. pylori may lead to recovery of vitamin C secretion by gastric epithelium and enable regression of premalignant gastric lesions, thereby interrupting the Correa cascade of gastric carcinogenesis.

Analysis of the response time to involved-field radiotherapy in primary gastrointestinal low-grade B-cell lymphoma

BACKGROUND

Early-stage primary gastrointestinal (GI) low-grade B-cell lymphoma shows good therapeutic response to primary radiotherapy. However, there is no clear guideline for the evaluation of response to radiation therapy currently. The aim of this study was to analyze the relationship between the best response time and the clinical course after radiotherapy.

METHODS

Patients who underwent radiotherapy for treatment of primary GI low-grade B-cell lymphoma from September 2007 to December 2018 at Seoul St. Mary's Hospital were included. Early responders were defined by best response within 6 months after radiotherapy, and delayed responders after 6 months. Clinical and pathological factors associated with delayed response and survival analyses were performed to investigate the recurrence and survival during follow-up.

RESULTS

A total of 43 patients were evaluated and the number of gastric mucosa-associated lymphoid tissue and duodenal follicular lymphoma was 36 and 7, respectively. All of 43 patients showed complete remission to radiotherapy and the best response time after radiotherapy was a median of 3 months. There were 8 delayed responders with a median duration of 8.9 months. Early and delayed responders were characterized by a significant difference in depth of invasion beyond the mucosal layer.

CONCLUSIONS

Delayed responders did not show differences in oncological outcomes compared with early responders. They were allowed to watch and wait for an additional 6 to 12 months without further treatment.

Clinical efficacy of the modified Helicobacter pylori eradication therapy for Helicobacter pylori-negative gastric mucosa-associated lymphoid tissue lymphoma: a meta analysis

Background

Helicobacter pylori (HP) has been considered to be one of the primary causes of gastric mucosa-associated lymphoid tissue (MALT) lymphoma since 1993. Low-grade gastric MALT lymphoma with HP is widely treated with HP eradication therapy, according to each specific clinical situation. However, several studies and guidelines indicate that the modified HP eradication therapy is also valid for HP-negative gastric MALT lymphoma. The aim of this study was to perform a meta-analysis of the clinical efficacy of the modified HP eradication therapy for gastric MALT lymphoma without HP.

Methods

We searched studies that reported the response rate of the modified HP eradication therapy regimen for gastric MALT lymphoma without HP by using PubMed, Medline, and Ebsco from January 1971 until February 2019. All statistical analyses were carried out using R 3.5.3 (Mathsoft Company, Cambridge, MA, USA). The pooled response rate was expressed as a decimal. The heterogeneity test was performed using the I-squared (I²) statistic.

Results

A total of 14 studies were selected with a total of 148 patients with HP-negative gastric MALT lymphoma. The overall pooled response rate was 0.38 (95% confidence interval [CI]: 0.29–0.47). The combined estimate is I² = 57% (P < 0.01). The study subjects were categorized by factors (area of patients). The pooled response rate of the sub-groups (Korea, Japan, China, and Western countries) was 0.63 (95% CI: 0.50–0.76), 0.16 (95% CI: 0.05–0.30), 0.38 (95% CI: 0.20–0.55), and 0.57 (95% CI: 0.08–1.00). The response rate showed that the modified HP eradication therapy was effective for patients with HP-negative gastric MALT lymphoma, especially in Korea and Western countries.

Conclusion

Therefore, the modified HP eradication therapy can be considered an optional therapy for patients with low-grade HP-negative gastric MALT lymphoma. However, several limitations were revealed in the meta-analysis. Further systematic reviews and research are required.

[Diagnosis and Treatment of Gastric Mucosa-associated Lymphoid Tissue Lymphoma]

The stomach is the most common primary site of an extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) type, which is characterized by an indolent clinical course. A diagnosis of gastric MALT lymphoma requires an endoscopic biopsy that should be confirmed by an experienced pathologist. Gastric MALT lymphoma shows a variable endoscopic appearance, including erosion, erythema, discoloration, atrophy, ulcer, and subepithelial lesion. The distribution is often multifocal. Therefore, clinical suspicion and multiple biopsies are essential for an accurate diagnosis. Gastric MALT lymphoma is almost invariably associated with a Helicobacter pylori (H. pylori) infection. H. pylori eradication therapy is the mainstay of treatment, which must be delivered to all patients regardless of the H. pylori infection status or stage. For patients who have failed to achieve remission following eradication therapy, radiotherapy or chemotherapy can be considered. Radiotherapy is an effective treatment modality for a localized stage and shows excellent outcomes. In the presence of disseminated or advanced disease, chemotherapy and/or immunotherapy with the anti-CD20 monoclonal antibody, rituximab, can be applied. Treatment should be individualized according to the stage and symptoms, as well as the patients' preference. Given that the clinical course of gastric MALT lymphoma is usually indolent, watchful waiting may be an adequate strategy in selected cases where scheduled follow-up is guaranteed.

[Clinical Efficacy of Radiotherapy in Helicobacter pylori Negative or Unresponsive to Eradication Therapy Primary Gastric Mucosa-Associated Lymphoid Tissue Lymphoma]

Background/Aims

The eradication of Helicobacter pylori (H. pylori) is an effective treatment in gastric mucosa-associated lymphoid tissue (MALT) lymphoma associated with H. pylori infection. However, the treatment strategy in gastric MALT lymphoma patients who are H. pylori-negative or unresponsive to H. pylori eradication therapy remains controversial. In this study, we investigated the clinical efficacy of treatments other than H. pylori eradication therapy in these groups of patients.

Methods

This was a retrospective single-center study based on the medical records of patients diagnosed with gastric MALT lymphoma at Yeungnam University Medical Center between January 2005 and December 2016. Patients were treated with H. pylori eradication therapy, chemotherapy, or radiotherapy according to their H. pylori infection status and stage of gastric MALT lymphoma.

Results

Of the 68 eligible patients, 50 were enrolled in the study. Of the 42 patients with H. pylori-positive gastric MALT lymphoma, 36 (81.7%) were treated with H. pylori eradication therapy as primary treatment and 25 (69.4%) achieved a complete response (CR). Patients without a CR after H. pylori eradication therapy (n=11, 30.6%) received radiotherapy as a secondary treatment. Two patients with H. pylori-positive gastric MALT lymphoma and eight with H. pylori-negative gastric MALT lymphoma received radiotherapy as the primary treatment. CR was achieved in all 21 patients treated with radiotherapy as primary or secondary treatment. The 5-year progression-free survival rate after radiotherapy was 92.9%.

Conclusions

Radiotherapy may be a worthwhile treatment option in patients with H. pylori-negative MALT lymphoma or H. pylori-positive MALT lymphoma that is not responsive to H. pylori eradication therapy.

Clinical manifestations and epigenetic mechanisms of gastric mucosa associated lymphoid tissue lymphoma and long-term follow-up following Helicobacter pylori eradication

The current study aimed to summarize the clinical manifestations and identify the epigenetic mechanisms of gastric mucosa associated lymphoid tissue (MALT) lymphoma, as well as evaluate the long-term effects of Helicobacter pylori (H. pylori) eradication. A total of 122 patients with marginal zone B-cell lymphoma of primary gastric MALT lymphoma were enrolled in the present study. The clinical manifestations of gastric MALT lymphoma, including symptoms, H. pylori state and endoscopic type, were summarized. The response to therapy was evaluated in patients that underwent H. pylori eradication. Survival analysis was estimated using the Kaplan-Meier method. The expression of microRNA-383 (miR-383) in tumor tissues and cell lines was determined using reverse transcription quantitative polymerase chain reaction. Furthermore, bioinformatic analyses, luciferase reporter assays. and western blot analysis identified zinc finger E-box binding homeobox 2 (ZEB2) as a direct target gene of miR-383. An MTT assay was used to examine the function of miR-383 and ZEB2 in MALT lymphoma. The clinical symptoms of patients with gastric MALT lymphoma were non-specific and included epigastric pain, abdominal discomfort and bleeding. The majority of endoscopic types were classified as ulcer, erosion and mucosa edema. The H. pylori infection rate was 79.5% (97/122) and a total of 47 patients underwent eradication therapy. Lymphoma remission was achieved in 93.6% (44/47) of patients and complete remission (CR) was achieved in 74.4% (35/47). The median follow-up time was 38 months (range, 10-132 months) and the median time taken to achieve CR was 4 months (range, 3-7 months). The estimated 3-year survival rate was 90.3% and the 5-year survival rate was 76.2%. Therefore, it was determined that patients with stage I or II gastric MALT lymphoma are able to undergo H. pylori eradication as a first-line treatment and that the survival rate of patients undergoing this treatment is high. Furthermore, it was determined that the mechanism by which miR-383 and ZEB2 contribute to MALT lymphoma progression is by the targeting of ZEB2 by miR-383, which inhibits the proliferation of cancer cells.

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.

Novel developments in the pathogenesis and diagnosis of extranodal marginal zone lymphoma

Extranodal marginal zone lymphoma (EMZL), mostly represented by mucosa-associated lymphoid tissue (MALT) type, also referred to as MALT lymphoma, is a clinically heterogeneous entity within the group of low-grade B cell lymphomas that arises in a wide range of different extranodal sites, including the stomach, lung, ocular adnexa, and skin. It represents the third most common non-Hodgkin lymphoma in the Western world, and the median age of occurrence is around 60 years. One characteristic aspect in a subset of EMZL detectable in about 25% of the cases is the presence of specific chromosomal translocations involving the genes MALT1 and BCL10, which lead to activation of the NF-κB signaling pathway. Another unique aspect is that several infectious agents, such as Helicobacter pylori in the case of gastric EMZL, and autoimmune disorders, like Sjögren syndrome, have been implicated in the pathogenesis of this cancer. Recent findings as summarized in this review have further improved our understanding of the complex pathobiology of this disease and have been essential to better define novel treatment strategies. In addition, many of these specific features are currently being implemented for the diagnosis of EMZL.

Helicobacter pylori, gastric cancer and other gastrointestinal malignancies

In a retrospective study performed in California, U.S.A., ca. 3% of patients with gastric intestinal metaplasia (GIM) developed gastric cancer (GC) within a median time period of 4.6 years after diagnosis of GIM. This observation stresses the importance of targeted surveillance even in regions with a low GC prevalence. Patients with alcoholic liver disease as well as survivors of colorectal and lobular breast cancer were found to be at increased risk of secondary GC. A population-based Chinese study confirmed "serologic biopsy" as a useful screening tool for stratifying the individual risk of developing GC. Concerning GC therapy, a post hoc analysis of the MAGIC trial reported that regression of lymph node metastases, but not the tumor regression itself, predicts overall survival. Furthermore, in patients with high microsatellite instable tumors, perioperative chemotherapy leads to an increased risk of mortality. Two studies confirmed that eradication therapy is worthwhile as an initial treatment for gastric mucosa-associated lymphoid tissue (MALT) lymphoma irrespective of the H. pylori infection status and stage. An increased risk of a second primary malignancy including GC was observed in these patients treated with immuno/chemotherapy but not in patients treated solely with an H. pylori eradication treatment. With respect to gastrointestinal malignancies other than GC, discrepant data have been published regarding the association of H. pylori with pancreatic cancer whereas no association has been reported with esophageal squamous cell carcinoma. The majority of published studies still support an association of H. pylori with colon neoplasms.

Gastric mucosa-associated lymphoid tissue lymphoma and Helicobacter pylori infection: a review of current diagnosis and management

Helicobacter pylori (H. pylori)-associated gastritis is one of the most common infectious diseases in the United States, China and worldwide. Gastric mucosa-associated tissue lymphoma (MALT lymphoma) is a rare mature B-cell neoplasm associated with H. pylori infection that is curable by antibiotics therapy alone. The pathological diagnosis of gastric MALT lymphoma can be reached by histological examination, immunohistochemical staining and B-cell clonality analysis. H. pylori eradication is the choice of therapy for early-stage gastric MALT lymphoma. High response rates and long-term survival have been reported in refractory and localized diseases treated with low-dose radiation therapy. Systemic chemotherapy is recommended for advanced-stage gastric MALT lymphoma and cases with large B-cell lymphoma transformation. Recent advances in the pathological diagnosis and management of gastric MALT lymphoma are reviewed in this article.