Long-term clinical outcome of Helicobacter pylori eradication for gastric mucosa-associated lymphoid tissue lymphoma with a reference to second-line treatment

Diagnosis and Treatment for Gastric Mucosa-Associated Lymphoid Tissue (MALT) Lymphoma

Mucosa-associated lymphoid tissue (MALT) lymphoma, which was first reported in 1984, shows an indolent clinical course. However, the detailed clinicopathological characteristics of gastric MALT lymphoma have not been fully elucidated. We performed a literature search concerning the clinical features and treatment for gastric MALT lymphoma using PubMED. MALT lymphomas develop in single or multiple extranodal organs, of which the stomach is one of the most frequent sites; gastric MALT lymphoma accounts for 7% to 9% of all B-cell lymphomas, and 40% to 50% of primary gastric lymphomas. The eradication of Helicobacter pylori (H. pylori) is the first-line treatment for patients with gastric MALT lymphoma, regardless of the clinical stage. Approximately 60-90% of cases with stage I/II₁ disease only achieve a complete histological response via H. pylori eradication. In patients who do not respond to H. pylori eradication therapy, second-line treatments such as watch-and-wait, radiotherapy, chemotherapy, rituximab immunotherapy, and/or a combination of these are recommended. Thus, H. pylori plays a causative role in the pathogenesis of gastric MALT lymphoma, and H. pylori eradication leads to complete histological remission in the majority of cases.

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.

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.

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.

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.

Radiotherapy for mucosa-associated lymphoid tissue (MALT) lymphoma of the rectum: a case report

Extra-nodal mucosa-associated lymphoid tissue (MALT) lymphoma is frequently involved with the upper gastrointestinal tract, but rarely involved with the rectum. We report a case of rectal MALT lymphoma treated by radiotherapy (RT) alone. A 74-year-old woman with lower abdominal pain was diagnosed with MALT lymphoma by endoscopic mucosal resection (EMR). She was diagnosed as stage IE (Ann Arbor) MALT lymphoma by diagnostic work-up and review of EMR specimens. Definitive RT was performed with curative intent, totaling 30 Gy in 15 fractions. Complete response was confirmed by colonoscopy after RT with no progression observed at 5 years. Definitive RT is effective for rectal MALT lymphoma.

Radiotherapy for localized gastric mucosa-associated lymphoid tissue lymphoma: long-term outcomes over 10 years

This study aimed to assess the long-term outcomes of radiotherapy in patients with localized gastric mucosa-associated lymphoid tissue (MALT) lymphoma. Twenty-seven patients with Stage I gastric MALT lymphoma were treated with radiotherapy from 1999 to 2010. The median age was 65 years (range: 31-84). Fifteen patients were Helicobacter pylori-negative. Thirteen patients were treated with definitive radiotherapy alone. The other 14 patients who had refractory or residual disease following a prior treatment received salvage radiotherapy. The median dose of the radiotherapy was 30 Gy in 20 fractions (range: 30-39.5 Gy). The median follow-up period was 121 months (range: 8-176 months). The 5- and 10-year overall survival rates for all patients were 92% and 87%, respectively. No patients died from MALT lymphoma. Three patients died of other diseases at 8, 33 and 74 months after radiotherapy (myocardial infarction, pneumonia and hepatocellular carcinoma, respectively). No cases of local recurrence were observed during the follow-up period. There were no serious late gastric, liver or kidney complications during a median follow-up period of over 10 years. Two patients remain alive with distant metastases: a lung metastasis and an abdominal lymph node metastasis at 104 months and 21 months after radiotherapy, respectively. Excellent long-term local control was observed in patients with localized gastric MALT lymphoma after radiotherapy. However, lifelong follow-up should be conducted to detect cases of late recurrence, especially distant metastases.

Clinical Outcome of Eradication Therapy for Gastric Mucosa-Associated Lymphoid Tissue Lymphoma according to H. pylori Infection Status

Background. To evaluate the long-term outcome of H. pylori eradication therapy for gastric MALT lymphoma according to the presence of H. pylori infection. Methods. We retrospectively reviewed the medical records of patients between January 2001 and June 2014. The clinicopathologic characteristics and clinical outcomes were compared between H. pylori-positive and H. pylori-negative gastric MALT lymphoma groups. Results. Fifty-four patients were enrolled: 12 H. pylori-negative and 42 H. pylori-positive patients. The tumor was located more frequently in both the proximal and distal parts of the stomach (P = 0.001), and the percentage of multiple lesions was significantly greater in the H. pylori-negative group (P = 0.046). Forty-seven patients received initial eradication therapy, and 85% (35/41) of H. pylori-positive patients and 50% (3/6) of H. pylori-negative patients achieved complete remission after eradication therapy. The presence of multiple lesions was a predictive factor for unresponsiveness to H. pylori eradication (P = 0.024). The efficacy of eradication therapy (P = 0.133), complete remission (CR) maintenance period, and relapse after eradication therapy were not significantly different between the two groups. Conclusions. H. pylori eradication therapy could be an effective first-line treatment for localized H. pylori-negative gastric MALT lymphoma, especially for single lesions.

Concurrent gastric and pulmonary mucosa-associated lymphoid tissue lymphomas with pre-existing intrinsic chronic inflammation: a case report and a review of the literature

Herein, we report a rare case of concurrent gastric and pulmonary mucosa-associated lymphoid tissue (MALT) lymphomas. A 65-year-old man who had been diagnosed with Helicobacter pylori-positive gastric MALT lymphoma received eradication therapy and achieved complete remission. During follow-up, he developed de novo pulmonary MALT lymphoma as a sequela of pulmonary tuberculosis, accompanied by recurrent gastric MALT lymphoma. Polymerase chain reaction (PCR) products of the CDR3 region of the immunoglobulin heavy chain gene showed an overall polyclonal pattern with bands at 400 base pairs (bp) and 200 bp predominant in the pulmonary tissue, as well as two distinctive bands in the gastric tissue at 400 bp and 200 bp. This case suggests that multiorgan lymphomas are more likely to be independent from each other when they are far apart, involve different organ systems, and have independent precipitating factors.

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.

Characteristics of Helicobacter pylori-positive and Helicobacter pylori-negative gastric mucosa-associated lymphoid tissue lymphoma and their influence on clinical outcome

BACKGROUND

To compare clinicopathologic and molecular characteristics of low-grade gastric mucosa-associated lymphoid tissue lymphoma depending on Helicobacter pylori positivity and to find out a predictive factor for unresponsiveness to Helicobacter pylori eradication therapy in Korea.

METHODS

A total of 53 Helicobacter pylori-positive and 13 negative mucosa-associated lymphoid tissue lymphoma patients were enrolled, and tissues from 21 patients were investigated to examine the presence of t(11;18)(q21;q21) with fluorescence in situ hybridization. Clinicopathologic features such as the endoscopic appearance, dominant site of lesion, depth of invasion, clinical stage, and the existence of MALT1 gene rearrangement were compared between these two groups. Fifty-six patients who underwent H. pylori eradication therapy were divided into responder and nonresponder groups. The two groups were analyzed to calculate odds ratios for resistance to the eradication.

RESULTS

Helicobacter pylori-negative gastric mucosa-associated lymphoid tissue lymphoma patients averaged a more advanced clinical stage than H. pylori-positive (p = .023) patients. The frequency of t(11;18)/API2-MALT1 did not differ between H. pylori-positive (45.5%) and H. pylori-negative cases (55.6%). Thirty-eight of 51 (74.5%) H. pylori-positive patients achieved complete regression after the eradication, while 2 of 5 (40%) H. pylori-negative patients obtained regression. Presence of lesions in both distal and proximal parts of stomach (p = .041) and bearing of t(11;18)(q21;q21) (p = .007) were predictors for nonresponsiveness for H. pylori eradication.

CONCLUSIONS

Helicobacter pylori eradication could be performed as a primary therapy regardless of H. pylori status, and assessing t(11;18)/API2-MALT1 would be considered after failure to remission by H. pylori eradication.

Helicobacter pylori infection, chronic inflammation, and genomic transformations in gastric MALT lymphoma

Nowadays, it is believed that the main role in the development of gastric mucosa-associated lymphoid tissue (MALT) lymphoma plays Helicobacter pylori infection. This world-wide distributed bacteria is in charge of most cases of not only upper gastrointestinal tract disorders but also some of extragastric problems. Constant stimulation of the immune system causes a B-lymphocytes proliferation, which is considered to be responsible for the neoplastic transformation. On the other hand, there are 10%–20% of patients who do not respond to Helicobacter pylori eradication treatment. This group has often a chromosome translocation, which suggests that there is another unknown, so far, pathogenetic mechanism of MALT lymphoma. Majority of genetic abnormalities are connected with nuclear factor-κB (NF-κB) pathway, which activates the uncontrolled proliferation of neoplastic cells. Translocations already described in studies are t(11;18)(q21;q21), which is the most common, t(14;18)(q32;q21), t(14;18)(q32;q21), and t(3;14)(p14.1;q32). This non-Hodgkin's lymphoma is an indolent type originated outside lymph nodes. In more than 50% of cases, it occurs in the stomach. Occasionally, it can be found in salivary and thyroid gland, lung, breast, bladder, skin, or any other place in the human body. This paper is a review of the current knowledge on etiology, pathogenesis, treatment, and follow-up of gastric MALT lymphoma.

Non-gastric advanced mucosa-associated lymphoid tissue (MALT) lymphoma has worse prognosis than gastric MALT lymphoma even when treated with rituximab-containing chemotherapy

The aim of this study was to assess the clinical characteristics, treatment results, and analyze the prognostic factors among patients with extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma). We retrospectively reviewed 98 patients with MALT lymphoma consecutively diagnosed at the Cancer Institute Hospital. Eighty-one patients (82%) had localized disease and 17 patients (17%) had advanced disease. The primary site was gastric in 52, and extra-gastric in 46. With a median follow-up of 40 months, the estimated 3-year overall survival (OS) and progression free survival (PFS) of the entire group were 100% and 89%, respectively. Three-year PFS was significantly better in patients with gastric lymphoma than in those with non-gastric lymphoma (95% vs. 82%, p = 0.043). Patients with localized disease had significantly better 3-year PFS than those with advanced disease (94% vs. 73%, p = 0.026). Upon multivariate analysis, non-gastric lymphoma retained prognostic significance for PFS.

Recognition of changes in microvascular and microstructural patterns upon magnifying endoscopy predicted the presence of extranodal gastric MALToma

BACKGROUND AND OBJECTIVES: Gastric MALToma is difficult to recognize upon endoscopy. The aim of this study is to evaluate the application of microstructural and microvascular patterns in recognizing gastric MALToma on magnifying endoscopy. METHOD: All patients with diagnosis of gastric MALToma upon histology were recruited. They received magnifying endoscopy to observe for changes in microstructural and microvascular patterns. For patients with H pylori, eradication therapy would be given. For those without, appropriate treatments including gastrectomy or chemotherapy were commenced accordingly. Patients treated with H pylori eradication and non-operative treatments received follow-up magnifying endoscopy, and the same features were observed to predict the response to these treatments. RESULTS: From 2004 to 2007, nine patients presented to with epigastric pain, dyspepsia and belching. All patients were confirmed to have MALToma upon initial biopsy. Five patients had H pylori infection and received eradication. Two patients without H pylori were treated with Laparoscopic total gastrectomy. Two patients had pulmonary metastasis and treated with chemotherapy. Under magnifying endoscopy, all the lesions demonstrated either absence or irregular gastric pits. Moreover, there was consistently appearance of spider-shaped vascular pattern. Five patients with H pylori eradication had follow-up magnifying endoscopy, four of them showed resolution of abnormal vascular pattern and recovery of gastric pits. CONCLUSION: Abnormal spider like vasculature and disappearance of gastric pits are diagnostic features upon magnifying endoscopy for gastric MALToma. These features enhanced the diagnosis and assessment of extent of involvement during primary endoscopy, as well as follow-up surveillance for response to non-operative treatments.

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.

The Human Gastric Pathogen Helicobacter pylori and Its Association with Gastric Cancer and Ulcer Disease

With the momentous discovery in the 1980's that a bacterium, Helicobacter pylori, can cause peptic ulcer disease and gastric cancer, antibiotic therapies and prophylactic measures have been successful, only in part, in reducing the global burden of these diseases. To date, ~700,000 deaths worldwide are still attributable annually to gastric cancer alone. Here, we review H. pylori's contribution to the epidemiology and histopathology of both gastric cancer and peptic ulcer disease. Furthermore, we examine the host-pathogen relationship and H. pylori biology in context of these diseases, focusing on strain differences, virulence factors (CagA and VacA), immune activation and the challenges posed by resistance to existing therapies. We consider also the important role of host-genetic variants, for example, in inflammatory response genes, in determining infection outcome and the role of H. pylori in other pathologies—some accepted, for example, MALT lymphoma, and others more controversial, for example, idiopathic thrombocytic purpura. More recently, intriguing suggestions that H. pylori has protective effects in GERD and autoimmune diseases, such as asthma, have gained momentum. Therefore, we consider the basis for these suggestions and discuss the potential impact for future therapeutic rationales.

Target biopsy using magnifying endoscopy in clinical management of gastric mucosa-associated lymphoid tissue lymphoma

BACKGROUND AND AIM

We have reported the characteristics of magnified endoscopic images of gastric mucosa-associated lymphoid tissue (MALT) lymphoma before and after treatment. In this study, we investigated the diagnostic efficacy of magnified endoscopic images for target biopsy and evaluation of clinical remission.

METHODS

Twenty-one patients diagnosed with localized gastric MALT lymphoma were enrolled. Magnified endoscopy was performed prior to treatment and at a mean period of 1.8 months (1-6 months) after therapy (Helicobacter pylori eradication in 19 patients and radiation therapy in two patients). Microstructural pattern and abnormal vessels in the lesions were assessed, and corpus mucosa without lymphoma was divided into H. pylori-negative mucosa and H. pylori-positive mucosa. Biopsy was the gold standard in this study.

RESULTS

Nonstructural areas with abnormal vessels were observed in all patients before treatment. Fifteen patients achieved pathological complete remission. Disappearance of nonstructural areas and abnormal vessels after therapy was associated with pathological remission. Sensitivities of these findings for diagnosis were 76.9% and 85.7%, respectively, and the specificities were 87.5% and 85.7%, respectively. H. pylori eradication therapy was invalid in three patients with H. pylori-negative mucosa in magnified images.

CONCLUSIONS

Magnifying endoscopy may be useful for target biopsy of superficial gastric MALT lymphoma in clinical management.

Signet Ring Cell Gastric Cancer Occurring after Radiation Therapy for Helicobacter pylori-Uninfected Mucosa-Associated Lymphoid Tissue Lymphoma

Helicobacter pylori infection is the major cause for mucosa-associated lymphoid tissue (MALT) lymphoma and gastric cancers. On the other hand, gastric cancers are known to arise from gastric mucosal atrophy. We here report a case of signet ring cell gastric cancer that developed after radiation therapy for MALT lymphoma in H. pylori-uninfected patient whose stomach did not show gastric mucosal atrophy. A 58-year-old female was referred to our hospital for treatment of gastric MALT lymphoma. This patient was not infected with H. pylori, and upper gastrointestinal endoscopy revealed that she did not have gastric mucosal atrophy but had submucosal tumor-like MALT lymphoma lesion in the anterior wall of the upper gastric body. Since conventional eradication therapy was ineffective, her whole stomach was irradiated as a second-line therapy. The MALT lymphoma lesion turned into complete remission state after the therapy. The patient was followed every 6 months by upper gastrointestinal endoscopy for 4 years as complete remission until a newly developed decolorized depressed lesion was detected in the greater curvature of the proximal antrum, a completely different location from the MALT lymphoma lesion. A biopsy specimen from the lesion contained signet ring cell carcinoma, and she was successfully treated by endoscopic submucosal dissection. No signs of recurrence have been detected so far. The radiation therapy for MALT lymphoma might be associated with the occurrence of this signet ring cell gastric cancer, and since MALT lymphoma is indolent in nature, this case suggests that careful consideration is required when choosing the second-line therapy for MALT lymphoma patients.

The role of abdominal CT scan as follow-up after complete remission with successful Helicobacter pylori eradication in patients with H. pylori-positive stage I(E1) gastric MALT lymphoma

BACKGROUND

Eradication of Helicobacter pylori with antibiotics is the established initial treatment of patients with localized gastric mucosa-associated lymphoid tissue (MALT) lymphoma. However, there are few reports on follow-up modalities to identify sustained remission in patients who achieve complete remission (CR). We therefore investigated the role of abdominal computed tomography (CT) as follow-up after CR with H. pylori eradication.

PATIENTS AND METHODS

We retrospectively analyzed 122 patients with H. pylori-positive stage I(E1) gastric MALT lymphoma who achieved CR with successful H. pylori eradication.

RESULTS

The median follow-up after CR was 35 months (range 3-140 months). At a median of 17 months (range 12-21 months) after CR, 7 of 122 patients (5.7%) experienced lymphoma recurrence, all cases of which were confined to the gastric mucosa and were detectable only by endoscopy with multiple biopsies. At the time of recurrence, four of seven patients showed re-infection by H. pylori. Eradication therapy was successful in these patients, resulting in both bacterial eradication and tumor regression. Three patients who experienced histologic recurrence without H. pylori re-infection were observed by a watch and wait strategy and again achieved CR.

CONCLUSIONS

None of the patients with H. pylori-positive stage I(E1) gastric MALT lymphoma who experienced tumor recurrence after CR with successful H. pylori eradication showed recurrence at extragastric sites, including lymph nodes without gastric mucosal lesion. These findings indicate that endoscopic biopsies without abdominal CT scans are sufficient to detect recurrence in these patients.

Molecular Aspects of H. pylori-Related MALT Lymphoma

Helicobacter pylori-related extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue is a paradigm for malignancy arising in an inflammatory background. While the diagnosis of H. pylori gastritis is often straightforward, distinction between severe gastritis and early lymphoma can be difficult and requires careful assessment of clinical findings in addition to histological features and immunohistochemical results. A number of cytogenetic abnormalities have been discovered in H. pylori-related lymphomas and several have clinical importance, related to the responsiveness of lymphoma to H. pylori eradication therapy, but routine molecular studies are not widely utilized. While molecular methods may be used in equivocal cases, a trial of conservative therapy is warranted given the propensity for these lymphomas to regress with eradication of the organism. Once therapy is initiated, care must be taken to avoid a premature assignment of disease refractoriness because complete response can take several months to more than a year. Cases truly refractory to H. pylori eradication therapy may be treated with adjuvant chemoradiation with a high response rate.

Strategies for gastric cancer in the modern era

Gastric cancer is one of the most common neoplasms in Japan, and it is also the second leading cause of cancer-related deaths worldwide. Nowadays, infection with Helicobacter pylori (H. pylori) is a known risk factor for the development of gastric cancer. Therefore, gastric cancer should be considered as an infectious disease, and in fact, prophylactic eradication of H. pylori may prevent the development of metachronous gastric carcinoma. Before the role of H. pylori was understood, a different approach was used. Recently even after the cancer has developed, some newer therapeutic approaches have been pursued. These newer treatments have been summarized as “minimally invasive therapies” and use endoscopic or laparoscopic techniques. In addition, robotic approaches are being developed that seem to hold a great potential to change the surgical approach. Since basic understanding and treatment of the disease have both changed significantly over the last decade, we present a review of current advances in gastric cancer research and therapy.

Effect of Helicobacter bilis infection on human bile duct cancer cells

BACKGROUND

Helicobacter pylori infection is known to be associated with chronic atrophic gastritis, peptic ulcers, and gastric malignancies. However, the effects of other Helicobacter species have not been investigated extensively. In mice, a close relationship is observed between Helicobacter hepaticus and hepatocellular carcinoma, and Helicobacter species can be found in humans, most commonly in extragastric organs. There have also been reports that H. bilis may be associated with biliary malignancies in humans. The effect of H. bilis infection on a human bile duct cancer cell line was investigated in this study.

METHODS

We prepared HuCCT-1, the human bile duct cancer cell line, which was cocultured with H. bilis and cultured alone as a control. HuCCT-1 with and without H. bilis were transfected with the NF-kappaB, E2 transcription factor (E2F), and cyclic AMP response element (CRE) luciferase vectors. The activity of NF-kappaB between H. bilis and the infected and noninfected HuCCT-1 cells was also measured by dual luciferase reporter assay. The concentration of vascular endothelial growth factor (VEGF) in the cocultured medium and control medium were measured by ELISA. To investigate the effect of H. bilis infection on HuCCT-1 with regard to human umbilical vein endothelial cell (HUVEC) tube formation, HUVECs and fibroblasts were cocultured in 24-well plates with and without the conditioned medium.

RESULTS

NF-kappaB, E2F and CRE activity, production of VEGF, and angiogenesis in H. bilis-infected cell lines were enhanced compared with controls.

CONCLUSIONS

H. bilis infection in a human bile duct cancer cell line activates transcript factors such as NF-kappaB that stimulate production of VEGF and lead to enhancement of angiogenesis. H. bilis infection may play an important role in malignancies in the biliary tract.

Guidelines for the management of Helicobacter pylori infection in Japan: 2009 revised edition

BACKGROUND

Over the past few years, the profile of Helicobacter pylori infection has changed in Japan. In particular, the relationship between H. pylori and gastric cancer has been demonstrated more clearly. Accordingly, the committee of the Japanese Society for Helicobacter Research has revised the guidelines for diagnosis and treatment of H. pylori infection in Japan.

MATERIALS AND METHODS

Four meetings of guidelines preparation committee were held from July 2007 to December 2008. In the new guidelines, recommendations for treatment have been classified into five grades according to the Minds Recommendation Grades, while the level of evidence has been classified into six grades. The Japanese national health insurance system was not taken into consideration when preparing these guidelines.

RESULTS

Helicobacter pylori eradication therapy achieved a Grade A recommendation, being useful for the treatment of gastric or duodenal ulcer, for the treatment and prevention of H. pylori-associated diseases such as gastric cancer, and for inhibiting the spread of H. pylori infection. Levels of evidence were determined for each disease associated with H. pylori infection. For the diagnosis of H. pylori infection, measurement of H. pylori antigen in the feces was added to the tests not requiring biopsy. One week of proton-pump inhibitor-based triple therapy (including amoxicillin and metronidazole) was recommended as second-line therapy after failure of first-line eradication therapy.

CONCLUSION

The revised Japanese guidelines for H. pylori are based on scientific evidence and avoid the administrative restraints that applied to earlier versions.

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

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

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Management and long-term follow-up of early stage H. pylori-associated gastric MALT-lymphoma in clinical practice: an Italian, multicentre study

BACKGROUND/AIM

Data on management and long-term follow-up of Helicobacter pylori-associated MALT-lymphoma in clinical practice are scanty. We evaluate the long-term efficacy of H. pylori eradication on low-grade MALT-lymphoma, and the efficacy of further therapies in refractory patients.

METHODS

This study enrolled patients with stages I-II(1) MALT-lymphoma and H. pylori infection. H. pylori eradication was attempted in all patients. Patients with lymphoma persistence or progression following H. pylori treatments received further lymphoma treatments. Both 5-year and disease-free survivals were calculated.

RESULTS

Sixty patients (stage I/II(1): 50/10) were followed up for a median time of 65 months (range 7-156). H. pylori infection was successfully eradicated in 53 (88.3%) patients following three consecutive therapeutic attempts, and lymphoma regressed in 42 (79.2%) of these patients. Sixteen patients received anti-neoplastic treatments due to either lymphoma persistence or progression, and lymphoma was cured in 14 (87.5%) cases. At follow-up, lymphoma relapsed in 13/42 (30.9%) patients within a median time of 19 months (range 3-41), and all but 1 patient were cured with further therapies. Overall, lymphoma regression was achieved in 56 patients (93.3%). The 5-year and disease-free survivals were 94.7% and 74.6%, respectively.

CONCLUSIONS

In clinical practice, a conservative approach with antibiotic eradication seems to be appropriate management for early-stage MALT-lymphoma, with oncologic therapy being reserved for those patients who fail to respond to H. pylori therapy.

Antibodies to Helicobacter pylori and CagA protein are associated with the response to antibacterial therapy in patients with H. pylori-positive API2-MALT1-negative gastric MALT lymphoma

The aim of this study was to clarify predictive factors for response to eradication therapy in cases of Helicobacter pylori (H. pylori)-positive API2-MALT1-negative gastric mucosa-associated lymphoid tissue (MALT) lymphoma. Sixty-six patients who were examined for H. pylori infection and the presence of the API2-MALT1 chimeric transcript and who underwent H. pylori eradication therapy as first-line therapy, were enrolled in this study. Immunohistochemical markers (p53, Ki-67, and BCL10), microsatellite instability, loss of heterozygosity, serum levels of antibodies (anti-H. pylori and anti-CagA), and markers for gastritis (gastrin and pepsinogens) were examined, and the results were compared between patients whose tumors regressed completely after eradication therapy (responders) and patients whose tumors did not regress (non-responders). Of the 66 patients with localized gastric MALT lymphoma, 47 (71.2%) showed complete remission after eradication therapy. None of the H. pylori-negative (n = 9) and/or API2-MALT1-positive (n = 7) patients responded to antibacterial treatment. Of 44 patients with H. pylori-positive API2-MALT1-negative gastric MALT lymphoma, 38 (86.4%) showed complete remission after eradication therapy. Titers of antibodies against H. pylori and CagA protein were significantly higher in the responders than in the non-responders (P = 0.0235 and 0.0089, respectively). No significant difference between the groups was observed for the other factors. In conclusion, measurement of titers of serum antibodies to H. pylori and CagA protein may be useful for predicting the response to eradication therapy in patients with H. pylori-positive API2-MALT1-negative gastric MALT lymphoma.

Primary non-Hodgkin lymphomas in the small and large intestine: clinicopathological characteristics and management of 40 patients

To investigate the clinicopathological characteristics and optimal treatment modalities of primary non-Hodgkin lymphoma (NHL) in the small and large intestine. Forty patients with primary NHL in the small and large intestine were studied retrospectively. All cases were reclassified according to the World Health Organization (WHO) classification of lymphoma in 2001. Fourteen patients had primary disease in the small intestine, which were all of B-cell origin with diffuse large B-cell lymphoma (DLBCL) diagnosed in 5 of 14 (35.7%) patients and mucosa-associated lymphoid tissue (MALT) lymphoma in 8 of 14 (57.1%) patients. Ileum was the most commonly involved site (8 of 14 patients, 57.1%), followed by jejunum (2 of 14 patients, 14.3%) and duodenum (1 of 14 patients, 7.1%). Twenty-five patients had primary colorectal lymphoma, with B-cell origin accounting for 92.0% and T-cell origin for 8.0% of these patients. The ileocaecal region has the highest involved rate (13 of 25 patients, 52.0%), followed by colon (7 of 25 patients, 28.0%) and rectum (3 of 25 patients, 12.0%). Compared with surgery alone, post-operation chemotherapy or chemoradiotherapy can significantly improve DLBCL patients' event-free survival (EFS). However, no post-operation treatment modality can improve OS or EFS for patients with MALT lymphoma. B-cell lymphoma is the most common pathological type of intestinal lymphomas. Chemotherapy-containing treatment modality is an effective way to improve intestinal lymphoma patients' EFS, especially for those with DLBCL subtype.

Long-term clinical outcome of helicobacter pylori-negative gastric mucosa-associated lymphoid tissue lymphoma is comparable to that of h. pylori-positive lymphoma

GOALS AND BACKGROUND

Little is still known regarding the clinical features and prognosis of gastric mucosa-associated lymphoid tissue (MALT) lymphoma without Helicobacter pylori (H. pylori) infection.

STUDY

From January 1996 to April 2006, a total of 185 patients with gastric MALT lymphoma were enrolled at Seoul National University Hospital. To assess the differences in clinical characteristics and long-term outcomes between H. pylori-negative (n=29, 15.7%) and H. pylori-positive (n=156, 84.3%) cases, we compared these 2 types of lymphoma.

RESULTS

The overall median follow-up period was 39 months. There were no significant differences between the 2 groups in terms of age, macroscopic phenotype, or histologic grade. H. pylori-negative group showed male predominancy (72.4%) and higher percentage of proximal stomach location (62.1%). Although H. pylori-negative lymphomas were more frequently presented as advanced disease (stage IIE or IV, 37.9%), no significant differences in both the overall complete response and overall survival rates were observed between the 2 groups.

CONCLUSIONS

Our results suggest that H. pylori-negative gastric MALT lymphoma shows a favorable long-term outcome, which is comparable to that of H. pylori-positive lymphoma.

Treatment of low-grade gastric MALT-lymphoma unresponsive to Helicobacter pylori therapy: a pooled-data analysis

The most favourable therapeutic strategy for gastric MALT-lymphoma not responding to Helicobacter pylori eradication still remains unclear, neither official guidelines nor randomised studies being available. We therefore performed a systematic review of the literature to evaluate the efficacy of different therapeutic approaches in these patients. Data regarding 315 patients were valuable, and lymphoma remission following the first therapeutic attempt was achieved in 90.1% cases. The most used therapy was radiotherapy (112 patients), followed by surgery (80 patients) and chemotherapy (68 patients), whilst a combination therapy was less frequent. Radiotherapy achieved a higher remission rate as compared to chemotherapy (97.3 vs. 85.3%; P = 0.007), being similar to surgery (97.3 vs. 92.5%; P = 0.2). No difference emerged when comparing lymphoma remission rate achieved by a single therapy with that of combined treatments (89.6 vs. 96.4%; P = 0.6). This is the first pooled-data analysis assessing the efficacy of different oncologic therapeutic approaches to treat gastric MALT-lymphoma unresponsive to H. pylori eradication. Radiotherapy seems to be the most suitable treatment in these patients.

Complete long-term response to radiotherapy of gastric early-stage marginal zone lymphoma resistant to both anti-Helicobacter pylori antibiotics and chemotherapy

BACKGROUND

The optimal approach to patients with gastric lymphoma of extranodal mucosa-associated lymphoid tissue (MALT) that resist to anti-Helicobacter pylori (HP) eradication therapy is still to be defined.

PATIENTS AND METHODS

From January 1997 to December 2004, we observed 24 patients affected with newly diagnosed early-stage and HP-positive gastric lymphoma of the MALT type. Five of them resisted to oral anti-HP antibiotic regimens and to subsequent one (two patients) or two (three patients) chemotherapy regimens. Age ranged between 51 and 77 years (median 70); three were females. Translocation (11;18) was ascertained in one subject. They were admitted to local radiation therapy with a total dose of 30 Gy.

RESULTS

All such resistant patients achieved complete remission after radiotherapy. No relapses were observed after 21, 45, 48, 52, and 67 months of uninterrupted follow-up. Early toxicity was very low and consisted of mild nausea. Late toxicity or secondary malignancy was not recorded so far.

CONCLUSIONS

Radiotherapy proved to be effective and safe for early-stage HP-positive gastric extranodal lymphoma of MALT type that is resistant to anti-HP eradication antibiotics and to following chemotherapy. Radiotherapy might be suggested as principal salvage therapy after resistance to HP eradication, instead of chemotherapy.

Characteristics of magnified endoscopic images of gastric extranodal marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue, including changes after treatment

BACKGROUND

The utility of magnifying endoscopy for diagnosis of epithelial tumors has been reported, but there are few reports for nonepithelial tumors.

OBJECTIVE

To determine the characteristics of magnified images of gastric extranodal marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT lymphoma) before and after treatment.

DESIGN

This was a retrospective study.

SETTING

Endoscopy Unit, Hokkaido University Hospital.

PATIENTS

Eleven patients diagnosed with MALT lymphoma were enrolled.

INTERVENTIONS

The microstructural pattern, collecting venules, and abnormal vessels in gastric MALT lymphoma were assessed before treatment and at 4 to 7 months after treatment by using magnifying endoscopy. MAIN OUTCOME MEASUREMENT AND RESULTS: The characteristics of magnified endoscopic images before treatment were the disappearance of gastric pits and the appearance of abnormal vessels. Ten cases of Helicobacter pylori-infected MALT lymphoma were treated by H. pylori eradication, and 1 H. pylori-negative case was treated by radiation therapy after eradication therapy. Ten patients achieved complete disease remission. After the treatment, recovery of gastric pits and subepithelial capillary network, and the disappearance of abnormal vessels were revealed by magnifying endoscopy.

LIMITATION

This was a small pilot study.

CONCLUSIONS

Magnified findings of gastric MALT lymphoma before and after therapy seem to correlate with complete response and no response.

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

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

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

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

Long-term results of stomach-conserving therapy in gastric MALT lymphoma

PURPOSE

To evaluate long-term results of stomach-conserving therapy and to assess the value of histological probable minimal residual disease (pMRD) in predicting outcome in patients with gastric MALT lymphoma.

MATERIALS AND METHODS

We studied 115 patients with stage I-II(2) gastric MALT lymphoma treated between 1975 and 2002. Initially, first-line treatment consisted of radiotherapy only. Since 1994 most patients were primarily treated with Helicobacter pylori eradication; radiotherapy was used in case of eradication failure. To assess the value of pMRD, first follow-up biopsy samples classified as compete remission (CR) according to classical clinico-pathological criteria and biopsy samples 1 year after assessment of histological CR were reviewed; results were related to outcome.

RESULTS

Following radiotherapy only (n=56) 96% achieved a clinical CR; 10-year cancer-specific survival rate was 94%. Following H. pylori eradication only (n=35) CR-rate was 43% and after additional treatment 89%; 5-year cause-specific survival was 93%. There was no difference in relapse rate following initial histological CR or pMRD.

CONCLUSIONS

Patients with early stage gastric MALT lymphoma have a favorable long-term outcome following conservative treatment. Outcome after H. pylori eradication followed by delayed radiotherapy on indication was excellent. In our series pMRD was not associated with increased risk of recurrence.

A Four-Dimensional CT-Based Evaluation of Techniques for Gastric Irradiation

PURPOSE

To evaluate three-dimensional conformal (3D-CRT), intensity-modulated (IMRT) and respiration-gated radiotherapy (RGRT) techniques for gastric irradiation for target coverage and minimization of renal doses. All techniques were four-dimensional (4D)-CT based, incorporating the intrafractional mobility of the target volume and organs at risk (OAR).

METHODS AND MATERIALS

The stomach, duodenal C-loop, and OAR (kidneys, liver, and heart) were contoured in all 10 phases of planning 4D-CT scans for five patients who underwent abdominal radiotherapy. Planning target volumes (PTVs) encompassing all positions of the stomach (PTV(all phases)) were generated. Three respiratory phases for RGRT in inspiration and expiration were identified, and corresponding PTV(inspiration) and PTV(expiration) and OAR volumes were created. Landmark-based fields recommended for the Radiation Therapy Oncology Group (RTOG) 99-04 study protocol were simulated to assess PTV coverage. IMRT and 3D-CRT planning with and without additional RGRT planning were performed for all PTVs, and corresponding dose volume histograms were analyzed.

RESULTS

Use of landmark-based fields did not result in full geometric coverage of the PTV(all phases) in any patient. IMRT significantly reduced mean renal doses compared with 3D-CRT (15.0 Gy +/- 0.9 Gy vs. 20.1 Gy +/- 9.3 Gy and 16.6 Gy +/- 1.5 Gy vs. 32.6 Gy +/- 7.1 Gy for the left and right kidneys, respectively; p = 0.04). No significant increase in renal sparing was seen when adding RGRT to either 3D-CRT or IMRT. Tolerance doses to the other OAR were not exceeded.

CONCLUSIONS

Individualized field margins are essential for gastric irradiation. IMRT plans significantly reduce renal doses, but the benefits of RGRT in gastric irradiation appear to be limited.

Mucosa-associated lymphoid tissue lymphoma: molecular pathogenesis and clinicopathological significance

Mucosa-associated lymphoid tissue (MALT) lymphoma is a low-grade tumor closely associated with chronic inflammation such as that of Helicobacter pylori gastritis, Sjogren's syndrome, and Hashimoto's thyroiditis. Tumor regression by H. pylori eradication alone is well known in gastric MALT lymphoma, but some tumors occur in the absence of pre-existing chronic inflammation. The understanding of MALT lymphoma biology has significantly improved, and recurrent cytogenetic alterations have been detected. These include the trisomies 3 and 18, and the translocations t(11;18)(q21;q21), t(1;14)(p22;q32), t(14;18)(q32;q21), and t(3;14)(p14.1;q32). At least some of these alterations result in the constitutive activation of the nuclear factor (NF)-kappaB pathway, and may exert anti-apoptotic action. Apoptosis inhibitor 2-MALT lymphoma-associated translocation 1 (API12-MALT1) fusion, resulting from t(11;18)(q21;q21), is specific to, and is the most common in, MALT lymphomas, and its clinicopathological significance has been studied extensively. The focus of the present review is on the recent progress made in elucidating MALT lymphomagenesis and its clinicopathological impact, especially in terms of the effect of API2-MALT1 fusion on this unique tumor.

American College of Gastroenterology guideline on the management of Helicobacter pylori infection

Helicobacter pylori (H. pylori) remains a prevalent, worldwide, chronic infection. Though the prevalence of this infection appears to be decreasing in many parts of the world, H. pylori remains an important factor linked to the development of peptic ulcer disease, gastric malignanc and dyspeptic symptoms. Whether to test for H. pylori in patients with functional dyspepsia, gastroesophageal reflux disease (GERD), patients taking nonsteroidal antiinflammatory drugs, with iron deficiency anemia, or who are at greater risk of developing gastric cancer remains controversial. H. pylori can be diagnosed by endoscopic or nonendoscopic methods. A variety of factors including the need for endoscopy, pretest probability of infection, local availability, and an understanding of the performance characteristics and cost of the individual tests influences choice of evaluation in a given patient. Testing to prove eradication should be performed in patients who receive treatment of H. pylori for peptic ulcer disease, individuals with persistent dyspeptic symptoms despite the test-and-treat strategy, those with H. pylori-associated MALT lymphoma, and individuals who have undergone resection of early gastric cancer. Recent studies suggest that eradication rates achieved by first-line treatment with a proton pump inhibitor (PPI), clarithromycin, and amoxicillin have decreased to 70-85%, in part due to increasing clarithromycin resistance. Eradication rates may also be lower with 7 versus 14-day regimens. Bismuth-containing quadruple regimens for 7-14 days are another first-line treatment option. Sequential therapy for 10 days has shown promise in Europe but requires validation in North America. The most commonly used salvage regimen in patients with persistent H. pylori is bismuth quadruple therapy. Recent data suggest that a PPI, levofloxacin, and amoxicillin for 10 days is more effective and better tolerated than bismuth quadruple therapy for persistent H. pylori infection, though this needs to be validated in the United States.

Therapy of gastric mucosa associated lymphoid tissue lymphoma

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

Therapy of gastric mucosa-associated lymphoid tissue lymphoma

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

Advances on the treatment of gastric mucosa-associated lymphoid tissue lymphoma

Gastric mucosa-associated lymphoid tissue (MALT) lymphomas are rare in the gut, and its occurrence rate was 1% to 5% of the malignant tumors. In histological type, most of them are non-Hodgin's lymphomas, while Hodgin's lymphomas are seldom seen. There have been a lot of controversies on the optimal treatments of gastric MALT lymphomas for a long time. Surgery was traditionally considered as the most important approach to cure the disease. However, anti-H. pylori therapy has been regarded as an alternative method since H. pylori infection was found to be relevant with the pathogenesis of gastric MALT lymphomas. In this article, we reviewed the current status and recent advances on the treatment of this disease.

Radiotherapy for low-grade gastric marginal zone lymphoma: a retrospective study

BACKGROUND

We evaluated the efficacy and toxicity of radiotherapy (RT) in patients with low-grade gastric marginal zone lymphoma.

METHODS

A retrospective review of consecutive cases of gastric marginal zone lymphoma treated by radical RT at the Peter MacCallum Cancer Centre and Radiation Oncology Victoria between January 1980 and September 2003 was carried out.

RESULTS

Eighteen patients (11 men and 7 women) were identified. The median age at commencement of RT was 65 years (range 42-84 years). Prior treatment included Helicobacter pylori eradication in 12 patients, chemotherapy in 7 and surgery in 2, whereas 2 patients had no prior therapy. The median time to progression after commencement of last treatment before RT was 4.8 months (range 0-129.4 months). The radiation fields included the stomach plus perigastric and coeliac nodes in 15 patients (83%), stomach plus spleen in 2 patients (11%) and stomach plus para-aortic nodes in 1 patient (6%). The median RT dose was 30 Gy (range 30-36 Gy) in a median 20 fractions (range 17-24 fractions). One patient required treatment interruption for acute toxicity. A complete response on post-RT biopsies was achieved in 17 of 18 patients (94%). With a median follow up of 4.5 years after RT, 3 of these 17 patients (18%) have had a recurrence. At the last follow up, 11 patients were alive in continuous complete histological remission. No late renal toxicity was identified.

CONCLUSION

Radiotherapy is an effective, well-tolerated treatment for patients with low-grade gastric marginal zone lymphoma, including those who have had prior therapy.

Helicobacter pylori-negative gastric mucosa-associated lymphoid tissue lymphoma: a clinicopathologic and molecular study with reference to antibiotic treatment

BACKGROUND

The majority of gastric mucosa-associated lymphoid tissue (MALT) lymphoma develops in Helicobacter pylori-associated chronic gastritis. Little is still known regarding the clinicopathologic features of gastric MALT lymphoma not associated with H. pylori infection.

METHODS

One hundred thirty-seven patients with gastric MALT lymphoma, in whom H. pylori status was evaluated using at least both serology and histology, were enrolled. Clinical, histopathologic, and molecular findings were compared between H. pylori-negative group (n = 12; 9%) and H. pylori-positive group (n = 125; 91%). t(11;18)(q21;q21) was investigated by reverse-transcription polymerase chain reaction and interphase fluorescence in situ hybridization.

RESULTS

In cases without diffuse large B-cell lymphoma (DLBCL) component, H. pylori-negative lymphomas located more frequently in the proximal stomach (70%), less frequently appeared as superficial type (40%), and frequently invaded the submucosa or beyond (70%). Histologically, lymphoepithelial lesions (57%), lymphoid follicles (43%), and background mucosal atrophy (50%) in the H. pylori-negative group were less frequent than in the H. pylori-positive group (91%, 93%, and 100%, respectively). The frequencies of t(11;18)(q21;q21) (100%) and BCL10 nuclear expression (100%) in the H. pylori-negative group were significantly higher than in the H. pylori-positive group (2% and 27%, respectively). Response to antibiotic treatment was observed not only in the H. pylori-positive group (75%), but also in the H. pylori-negative group (2 of 7 patients, 29%). In cases with a DLBCL component, such differences were not observed between the 2 groups.

CONCLUSIONS

H. pylori-negative gastric MALT lymphoma is characterized by frequent t(11;18)(q21;q21). Antibiotic treatment should be considered also for this disease, although cases with t(11;18)(q21;q21) may need additional strategies.

Non-Hodgkin's lymphoma of mucosa-associated lymphoid tissue

The concept of mucosa-associated lymphoid tissue (MALT) lymphomas was introduced by Isaacson and Wright [Cancer 1983; 52:1410-1416] in 1983. After more than 20 years of clinical research MALT lymphomas are now recognized as a distinct subtype of non-Hodgkin's lymphoma (NHL) with unique pathogenic, histological, and clinical features. Although this subtype of NHL occurs frequently, optimal management remains elusive. This manuscript reviews features of the clinical presentation, diagnosis, pathology, molecular characteristics, and management of both gastric and non-gastric MALT lymphoma.

Gastric inflammatory fibroid polyp treated with Helicobacter pylori eradication therapy

Gastric inflammatory fibroid polyps (IFPs) are rare benign lesions that occur in the distal stomach. We describe a 56-year-old woman with Helicobacter pylori (H. pylori)-positive gastric IFP treated with eradication. Endoscopic examination revealed a submucosal tumor, 35 mm in diameter, with an ulcerated apex at the antrum. H. pylori were positive by both histology and tissue culture, and eradication (a proton pump inhibitor, amoxicillin, and clarithromycin) was performed. After 6 months, the tumor morphologically changed and decreased in size. This case suggests that H. pylori may play a role in the pathogenesis of gastric IFPs.

Helicobacter pylori: present status and future prospects in Japan

The discovery of Helicobacter pylori has already changed the natural history of peptic ulcer disease, with most patients being cured at their first presentation. Similarly, the incidence of gastric cancer and other diseases related to H. pylori are likely to be greatly reduced in the near future. Isolation of the spiral intragastric bacterium H. pylori totally reversed the false dogma that the stomach was sterile, and it taught us that chronic infectious disease can still exist in modern society. Helicobacter pylori's unique location, persistence, and evasion of the immune system offer important insights into the pathophysiology of the gut. Also, the fact that it was overlooked for so long encourages us to think "outside the box" when investigating other diseases with obscure etiologies. We should consider such provocative scientific ideas as bridges to the future disease control.