Low-grade MALT lymphoma of the stomach: a review of treatment options

Low-grade malt lymphoma of the nasopharynx in young adults: Successful treatment of a rare diagnosis at a rare site by radiotherapy

INTRODUCTION

Mucosa Associated Lymphoid Tissue (MALT) lymphoma is the third most common subgroup of Non-Hodgkin's lymphoma and is the most common type of primary extranodal lymphoma. They are rarely found in the nasopharyngeal region and their mean age at presentation is the sixth decade of life.

MATERIALS AND METHODS

We present the clinical, pathological, treatment and 5-year follow-up data of 5 cases of nasopharyngeal MALT lymphoma treated with definitive radiotherapy at our hospital, between 2009 and 2011.

RESULTS

The average age of diagnosis was 27 years which is more than a decade earlier than what has been reported previously. Clinical symptoms included nasal obstruction, tinnitus and hearing loss. All five patients had locoregional disease. They were treated by definitive radiotherapy to a dose between 30 to 40 Gy. At 5 years of follow-up, 4 patients were in complete remission while one had disease relapse.

CONCLUSION

The younger age of presentation compared to older reports in this rare subsite was an interesting finding in our study. The authors speculate that rising levels of particulate air pollution may have played a part in the etiology in this younger population. Our series shows that despite the younger age, the disease displays an indolent course and responds well to radiotherapy alone as the primary treatment. Recurrence or disseminated disease is also highly treatable with systemic chemotherapy.

Development of Organ-Preserving Radiation Therapy in Gastric Marginal Zone Lymphoma

Simple Summary

Gastric marginal zone lymphoma of the stomach is a rare cancer type primarily treated with oral proton pump inhibitors. If the disease does not respond to this, radiation is the treatment of choice. This review presents the development of radiation therapy over the last decades. Earlier, the stomach was surgically removed and irradiation was performed using large-field techniques and high doses of radiation. Currently, the standard treatment is the use of small-volume radiation therapy (with few side effects) with the preservation of the stomach, which provides excellent outcomes. In addition, this paper provides an outlook on current studies and possible future developments.

Abstract

Gastric marginal zone lymphoma (gMZL) of mucosa-associated lymphoid tissue (MALT) may persist even after H. pylori eradication, or it can be primarily Helicobacter pylori (H. pylori) independent. For patients without the successful eradication of lymphoma, or with progressive disease, treatment options have historically included partial or total gastrectomy. Presently, in these instances, curative radiation therapy (RT) is the current standard of care. This review emphasizes the historically changing role of radiation therapy in gMZL, progressing from large-volume RT without surgery, to localized RT, on its own, as a curative organ-preserving treatment. This overview shows the substantial progress in radiation therapy during the recent two to three decades, from high-dose, large-field techniques to low-dose, localized target volumes based on advanced imaging, three-dimensional treatment planning, and advanced treatment delivery techniques. RT has evolved from very large extended field techniques (EF) with prophylactic treatment of the whole abdomen and the supradiaphragmatic lymph nodes, applying doses between 30 and 50 Gy, to involved-field RT (IF), to the current internationally recommended involved site radiation therapy (ISRT) with a radiation dose of 24–30 Gy in gMZL. Stage-adapted RT is a highly effective and safe treatment with excellent overall survival rates and very rare acute or late treatment-related toxicities, as shown not only in retrospective studies, but also in large prospective multicenter studies, such as those conducted by the German Study Group on Gastrointestinal Lymphoma (DSGL). Further de-escalation of the radiation treatments with low-dose 20 Gy, as well as ultra-low-dose 4 Gy radiation therapy, is under investigation within ongoing prospective clinical trials of the International Lymphoma Radiation Oncology Group (ILROG) and of the German Lymphoma Alliance (GLA).

Involved-site radiotherapy for Helicobacter pylori-independent gastric MALT lymphoma: 26 years of experience with 178 patients

Treatment options for Helicobacter pylori-independent gastric mucosa-associated lymphoid tissue (MALT) lymphoma (GML) include surgery, immunotherapy, chemotherapy, and radiation therapy (RT). The purpose of this study was to investigate the efficacy and safety of RT and routine endoscopic surveillance, hypothesizing that most patients are curable with RT alone. We queried a single institution database at a tertiary referral cancer center for patients with H pylori-independent GML treated with RT between 1991 and 2017. Response was assessed by follow-up endoscopies (EGDs) starting 10 to 12 weeks post-RT. Computed tomography scans were also part of the follow-up program, and positron emission tomography was added when clinically appropriate. We identified 178 patients (median age, 63 years; range, 25-89 years); 86% had stage I disease, 7% had stage II disease, and 7% had stage IV disease. Median RT dose was 3000 cGy over 20 fractions. Ninety-five percent of patients exhibited complete pathologic response on posttreatment EGD. Two patients experienced grade 3 toxicity, and 2 patients experienced in-field secondary malignancies. Over a median follow-up of 6.2 years, 9.6% experienced local failures, and 11.8% developed distant sites of disease. Five-year and 10-year overall survival were 94% and 79%, respectively, from last date of RT. RT is a highly effective and safe treatment for GML with excellent overall survival and very rare acute or late treatment-related toxicities. Favorable outcomes from this large retrospective sample of patients provide credible and compelling support for RT as standard of care for H pylori-independent GML.

[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.

Benefit of volumetric-modulated arc therapy over three-dimensional conformal radiotherapy for stage I-II extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue in the stomach: a dosimetric comparison

Purpose

To retrospectively analyze dosimetric parameters of volumetric-modulated arc therapy (VMAT) and three-dimensional conformal radiotherapy (3D-CRT) delivered to extranodal marginal zone B-cell lymphomas of mucosa-associated lymphoid tissue in the stomach (gastric MALT lymphoma) to find out advantages of VMAT and conditions for definite benefits of VMAT.

Materials and Methods

Fifty patients with stage I-II gastric MALT lymphoma received VMAT (n = 14) or 3D-CRT (n = 36) between December 2005 and April 2018. Twenty-seven patients were categorized according to whether the planning target volume (PTV) overlaps kidney(s). Dosimetric parameters were analyzed by dose-volume histogram.

Results

Radiation dose to the liver was definitely lower with VMAT in terms of mean dose (p = 0.026) and V₁₅ (p = 0.008). The V₁₅ of the left kidney was lower with VMAT (p = 0.065). For those with PTV overlapping kidney(s), the left kidney V₁₅ was significantly lower with VMAT. Furthermore, the closer the distance between the PTV and kidneys, the less the left kidney V₁₅ with VMAT (p = 0.037). Delineation of kidney(s) by integrating all respiratory phases had no additional benefit.

conclusions

VMAT significantly increased monitor units, reduced treatment time and radiation dose to the liver and kidneys. The benefit of VMAT was definite in reducing the left kidney V₁₅, especially in geometrically challenging conditions of overlap or close separation between PTV and kidney(s).

Effect of radiotherapy on prognosis of stage ⅠE/ⅡE gastric mucosa-associated lymphoid tissue lymphoma

AIM: To assess the effect of radiotherapy on prognosis of stage IE/IIE gastric mucosa-associated lymphoid tissue (MALT) lymphoma.

METHODS: The records of 35 patients treated for stage IE/IIE MALT lymphoma at Sun Yat-sen University Cancer Center between June 24, 1997 and October 27, 2011 were retrospectively reviewed, including 9 cases who received radiotherapy followed by chemotherapy, 11 cases who received surgery followed by chemotherapy, and 15 cases who received chemotherapy alone. The curves of progression-free survival (PFS) and overall survival (OS) were calculated by the Kaplan-Meier method, and their significance was calculated by the log-rank tests. The curves of PFS and OS were compared among the three groups of patients.

RESULTS: The median follow-up time was 44.50 mo (range, 0.67 to 155.10 mo). Ten cases recurred, including 3 cases receiving surgery followed by chemotherapy, and 7 cases receiving chemotherapy alone. By multiple comparisons, the curve of PFS for cases receiving radiotherapy followed by chemotherapy had a statistical difference compared to those receiving chemotherapy alone (P = 0.043), but showed no statistical difference compared to those receiving surgery followed by chemotherapy (P = 0.195). The curve of OS for cases receiving radiotherapy followed by chemotherapy did not differ significantly from that for cases receiving surgery followed by chemotherapy (P = 0.304). No severe adverse reactions such as gastric hemorrhage or perforation occurred in cases receiving radiotherapy followed by chemotherapy.

CONCLUSION: Radiotherapy followed by chemotherapy is associated with significantly longer PFS in the treatment of stage IE/IIE gastric MALT lymphoma compared to chemotherapy alone or surgery followed by chemotherapy, although OS had no significant difference in the three groups.

Acute pancreatitis as the first manifestation of duodenal MALT lymphoma

BACKGROUND

Possibly any tumor that can cause mechanical obstruction of the distal bile duct can induce acute pancreatitis. However, acute pancreatitis as the first clinical manifestation of duodenal lymphoma is extremely rare.

OBJECTIVE

To report the case of a patient with acute pancreatitis as an extremely rare first manifestation of duodenal MALT lymphoma and possible association with erythema nodosum.

METHODS

Case report of a 66-year-old woman who was diagnosed with acute pancreatitis caused by infiltration with duodenal lymphoma.

RESULTS

Acute pancreatitis was confirmed by CT imaging. Detailed investigation revealed a duodenal mass causing pancreatic injury. Histological analysis established the diagnosis of MALT lymphoma. The patient's medical history also included erythema nodosum. Complete remission of the malignancy was achieved with chemotherapy.

CONCLUSION

This is the first published case report of acute pancreatitis caused by the growth of duodenal MALT lymphoma. An association with erythema nodosum is possible.

Long-term outcomes and patterns of relapse of early-stage extranodal marginal zone lymphoma treated with radiation therapy with curative intent

PURPOSE

To report the long-term outcome and patterns of relapse of a large cohort of marginal zone lymphoma (MZL) patients treated with curative-intent radiation therapy (RT) alone.

PATIENTS AND METHODS

We reviewed the charts of 490 consecutive patients with stage IE or IIE MZL referred between 1992 and 2012 to our institution. Of those, 244 patients (50%) were treated with RT alone. Pathology was confirmed by hematopathologists at our institution. Patient and disease factors were analyzed for association with relapse-free survival (RFS) and overall survival (OS).

RESULTS

Median age of the cohort was 59 years, and median follow-up was 5.2 years. Ann Arbor stage was IE in 92%. Most common disease sites were stomach (50%), orbit (18%), non-thyroid head-and-neck (8%), skin (8%), and breast (5%). Median RT dose was 30 Gy. Five-year OS and RFS were 92% and 74%, respectively. Cumulative incidence of disease-specific death was just 1.1% by 5 years. Sixty patients (24%) developed relapse of disease; 10 were in the RT field. Crude rate of transformation to pathologically confirmed large-cell lymphoma was 1.6%. On multivariable analysis, primary disease site (P=.007) was independently associated with RFS, along with age (P=.04), presence of B-symptoms (P=.02), and International Prognostic Index risk group (P=.03). All disease sites except for head-and-neck had worse RFS relative to stomach.

CONCLUSION

Overall and cause-specific survival are high in early-stage extra-nodal MZL treated with curative RT alone. In this large cohort of 244 patients, most patients did not experience relapse of MZL after curative RT; when relapses did occur, the majority were in distant sites. Stomach cases were less likely to relapse than other anatomic sites. Transformation to large-cell lymphoma was rare.

Radiotherapy for gastric lymphoma: a planning study of 3D conformal radiotherapy, the half-beam method, and intensity-modulated radiotherapy

During radiotherapy for gastric lymphoma, it is difficult to protect the liver and kidneys in cases where there is considerable overlap between these organs and the target volume. This study was conducted to compare the three radiotherapy planning techniques of four-fields 3D conformal radiotherapy (3DCRT), half-field radiotherapy (the half-beam method) and intensity-modulated radiotherapy (IMRT) used to treat primary gastric lymphoma in which the planning target volume (PTV) had a large overlap with the left kidney. A total of 17 patients with gastric diffuse large B-cell lymphoma (DLBCL) were included. In DLBCL, immunochemotherapy (Rituximab + CHOP) was followed by radiotherapy of 40 Gy to the whole stomach and peri-gastric lymph nodes. 3DCRT, the half-field method, and IMRT were compared with respect to the dose-volume histogram (DVH) parameters and generalized equivalent uniform dose (gEUD) to the kidneys, liver and PTV. The mean dose and gEUD for 3DCRT was higher than for IMRT and the half-beam method in the left kidney and both kidneys. The mean dose and gEUD of the left kidney was 2117 cGy and 2224 cGy for 3DCRT, 1520 cGy and 1637 cGy for IMRT, and 1100 cGy and 1357 cGy for the half-beam method, respectively. The mean dose and gEUD of both kidneys was 1335 cGy and 1559 cGy for 3DCRT, 1184 cGy and 1311 cGy for IMRT, and 700 cGy and 937 cGy for the half-beam method, respectively. Dose-volume histograms (DVHs) of the liver revealed a larger volume was irradiated in the dose range <25 Gy with 3DCRT, while the half-beam method irradiated a larger volume of liver with the higher dose range (>25 Gy). IMRT and the half-beam method had the advantages of dose reduction for the kidneys and liver.

Helicobacter pylori infection in gastric mucosa-associated lymphoid tissue lymphoma

Gastrointestinal lymphoma is the most common type of extranodal lymphoma, and most commonly affects the stomach. Marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) and diffuse large B-cell lymphoma are the most common histologic types of gastric lymphoma. Despite its increasing incidence, diagnosis of gastric lymphoma is difficult at an earlier stage due to its nonspecific symptoms and endoscopic findings, and, thus, a high index of suspicion, and multiple, deep, repeated biopsies at abnormally and normally appearing sites in the stomach are needed. In addition, testing for Helicobacter pylori (H. pylori) infection and endoscopic ultrasonography to determine the depth of tumor invasion and involvement of regional lymph nodes is essential for predicting response to H. pylori eradication and for assessment of disease progression. In addition, H. pylori infection and MALT lymphoma development are associated, and complete regression of low-grade MALT lymphomas after H. pylori eradication has been demonstrated. Radiotherapy and/or chemotherapy can be used in cases that show poor response to H. pylori eradication, negativity for H. pylori infection, or high-grade lymphoma.

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

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

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

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

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

Radiotherapy in marginal zone lymphoma

Purpose

To evaluate the efficacy of radiotherapy (RT) for early-stage nodal and extranodal marginal zone lymphoma (MZL).

Materials and methods

Patients with stage I (n = 22) and stage II (n = 8) MZL, who were treated with RT were reviewed. The primary tumor localisation was in the orbita (n = 12), stomach (n = 8), head and neck other than the orbita (n = 8), breast (n = 1) and one case of marginal zone lymphoma of the skin (n = 1). The median radiotherapy dose was 40 Gy (5 to 45 Gy).

Results

The median follow-up time was 103 months. The 5-year overall survival and event-free survival rates were 85 ± 7% and 71 ± 9%, respectively. There was no infield recurrence. Recurrence occurred outside of the radiation field in six patients. The relapses were treated with salvage RT and had excellent local control (100%) at five years after salvage RT.

Conclusions

Localized extranodal MZL have an excellent prognosis following moderate-dose RT. RT is also an effective salvage therapy in cases of localized recurrence. Further clinical studies should evaluate the optimal dose for MZL.

Treatment of gastric marginal zone lymphoma of MALT type

IMPORTANCE OF THE FIELD

Gastric marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT type) represent approximately half of all cases of lymphomas arising in the stomach. They have been strongly associated with chronic Helicobacter pylori (H. pylori) gastritis. Treatment aimed at eradicating this infection results in lymphoma remissions in the majority of patients (approximately 80%) and this represents a unique case of anticancer treatment based on the eradication of the causing factor.

AREAS COVERED IN THIS REVIEW

The effects of H. pylori eradication in suppressing the growth of this lymphoma with particular emphasis on the long-term disease control results are presented in this review. Trials of different treatment modalities for patients not responding to antibiotics are also covered.

WHAT THE READER WILL GAIN

Understanding of the effects of H. pylori eradication on suppressing the growth of gastric MALT lymphoma. Readers will learn how to distinguish between clinical, histological and molecular remission of the lymphoma and will learn alternative treatments for patients with H. pylori-negative disease and for cases not responding to eradication.

TAKE HOME MESSAGE

Gastric MALT lymphoma has an indolent course and most patients can achieve durable disease control after only anti-H. pylori therapy. For patients not responding to antibiotics, randomized trials are needed to define the best treatment modality.

Radiation therapy for gastric wall metastasis from esophageal carcinoma

An 86-year-old man with dysphagia underwent gastrointestinal fiberscopy (GIF) and was found to have a circumferential type 3 advanced carcinoma in the upper thoracic esophagus and a type 2 tumor in the posterior wall of the gastric body. Microscopic examination of biopsy specimens of both tumors demonstrated moderately differentiated squamous cell carcinoma. He was diagnosed as having stage IVb (T3N0M1b) esophageal carcinoma with gastric wall metastasis. A total of 60 Gy in 30 fractions of three-dimensional conformal radiation therapy (3D-CRT) was first administered to the esophageal carcinoma, next to the gastric wall metastasis. Concurrent chemotherapy was not given because of the patient's refusal. No subjective morbidity was observed during the treatment. In the GIF study immediately after 3D-CRT, both esophageal and gastric wall tumors had attained a complete response. The dysphagia dissolved as the esophageal tumor shrunk. The patient has been doing well for 17 months after the start of 3D-CRT. No local recurrence was observed in either the esophagus or the stomach during follow-up GIF. Considering the dismal prognosis of esophageal carcinoma patients with intramural metastasis to the stomach, a watchful follow-up is needed.

Long-term outcome following Helicobacter pylori eradication in a retrospective study of 105 patients with localized gastric marginal zone B-cell lymphoma of MALT type

BACKGROUND

Treatment aimed at eradicating Helicobacter pylori infection results in lymphoma remission in most localized gastric mucosa-associated lymphoid tissue (MALT) lymphomas. The aim of this survey is to investigate the long-term effect of this therapeutic approach in a large series of patients.

METHODS

One hundred and five patients with localized gastric MALT lymphoma were initially treated only with H. pylori eradication regimens. Lymphoma responses were graded using the Wotherspoon score.

RESULTS

Helicobacter pylori, detected by histology in 81% of cases, was eradicated in all positive patients. Histological regression of the lymphoma was achieved in 78 of 102 assessable patients [76%, 95% confidence interval (CI): 67% to 84%] with complete remission (score 0-2) in 66 and partial remission (score 3) in 12. At a median follow-up time of 6.3 years, histological remission was consistently confirmed in 33 of 74 assessable patients, while 25 had score fluctuations (from 0 to 4) and 13 presented a lymphoma relapse (score 5). Only one patient had a distant progression. Transformation to a large-cell lymphoma was seen in two cases. The 5- and 10-year overall survival is 92% (95% CI: 84% to 96%) and 83% (95% CI: 70% to 91%), respectively. Only one patient died of lymphoma after transformation to a high-grade lymphoma.

CONCLUSIONS

Helicobacter pylori eradication resulted in complete lymphoma remission in the majority of cases. Long-term clinical disease control was achieved in most patients. A watch and wait policy appears to be safe in patients with minimal residual disease or histological-only local relapse.

Successful treatment of mucosa-associated lymphoid tissue lymphoma of the rectum with radiation therapy: report of a case

We report a case of Stage IE mucosa-associated lymphoid tissue lymphoma arising in the rectum, which was successfully treated with radiotherapy. A 60-year-old man had several months of altered bowel habit with rectal bleeding and was found to have a large rectal tumor with no evidence of distant spread. Histologic studies showed this to be a mucosa-associated lymphoid tissue lymphoma. The patient received 45 Gy in 25 fractions with external beam radiotherapy during 5 weeks. The treatment was well tolerated and review at 41 months revealed no evidence of recurrence.

Recurrent gastric perforation as a late complication of radiotherapy for mucosa-associated lymphoid tissue lymphoma of the stomach

Radiation therapy can be used to treat Helicobacter pylori-negative or eradication-refractory extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) of the stomach. We report a case of gastric perforation which occurred more than 1 year after the completion of radiotherapy for H. pylori eradication-refractory gastric MALT lymphoma, and then recurred shortly afterwards. This was considered to be a late complication of radiation toxicity. Although gastric perforation due to radiotherapy has been reported very rarely in the past, even in advanced disease, this case shows that perforation can develop in patients with superficial disease and can relapse.

Therapy of gastric mucosa associated lymphoid tissue lymphoma

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

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

PURPOSE

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

METHODS AND MATERIALS

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

RESULTS

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

CONCLUSIONS

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

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.

Primary extranodal lymphomas of gastrointestinal localizations: a single institution 5-yr experience

This study is aimed at comparison of patients with extranodal lymphomas based on pathohistological findings differences (MALT vs non-MALT) as well as regarding gastric and non-gastric localization, and determining the significance of clinical-laboratory parameters with respect to therapeutic response and length of survival. A total of 56 patients with extranodal non-Hodgkin's lymphomas of the gastrointestinal tract were evaluated over a 5-yr period. Regarding the localization of the disease, the stomach was most frequently affected, 39 patients (70%); followed by small and large intestines, 17 patients. As for the pathohistological findings, MALT lymphoma accounted for 70%, DLBCL 25%, while other subtypes accounted for 5%. Patients' distribution was analyzed according to CS based on both Ann Arbor and Lugano systems; however, the difference obtained between the groups was not statistically significant in both staging types of patients. Statistically significant difference in patients' distribution was not found with respect to IPI index, bone marrow infiltration, anemia, hypoalbuminemia, or histological subtype and localization. Difference in survival between patients according to the pathohistological type was not statistically significant also according to the type of the affected gastrointestinal tract organ. Statistical significance of difference according to survival probability was obtained based on age (survival is longer in patients over 55 yr of age); according to CS and according to Ann Arbor and Lugano classifications (the patients with lower CS live significantly longer); according to IPI index (the survival is significantly longer in patients with lower probability: IPI-0,1, and 2), as well as patients free of bone marrow infiltration whose survival is also significantly longer.

Germline variations of the topoisomerase IIα gene as risk factors for primary gastric B-cell lymphoma

We investigated if germline variations of the Topoisomerase II alpha gene could predispose patients with chronic Helicobacter pylori infection to develop gastric lymphoma and conducted a mutation detection of the entire promoter region. Single marker and haplotype analysis did not reveal any associations with development of gastric lymphoma in general, histological grade or stage of disease (P>0.05). No genetic variations in the promotor region were found in 92 chromosomes of lymphoma patients and controls and linkage disequilibrium indicated a highly conserved genomic region. The results of our work exclude genetic variations as predisposing factors of primary gastric B-cell lymphoma development.

Infectious agents in mucosa-associated lymphoid tissue-type lymphomas: pathogenic role and therapeutic perspectives

Mucosa-associated lymphoid tissue (MALT) lymphoma probably constitutes the best in vivo model showing how complex interplay between B lymphocytes and the surrounding microenvironment may lead to a neoplastic disorder. After the seminal discovery of the pathogenic association between Helicobacter pylori and gastric MALT lymphomas, evidence suggests the possible involvement of other infectious agents in the development of MALT lymphomas arising at different body sites. Although several other bacteria (Borrelia burgdorferi, Campylobacter jejuni, and Chlamydia psittaci) and viruses (Hepatitis C virus) seem to play a role in lymphomas presenting at different locations, a possible common pathogenic mechanism is emerging. Several lines of evidence suggest that different infectious agents might provide a chronic antigenic stimulation that elicits host immune responses able to promote clonal B-cell expansion. This model is also substantiated by the increasing number of patients with MALT lymphomas who exhibit objective clinical responses after antimicrobial therapy. A multidisciplinary approach is critical to better understand the complex etiopathogenesis of MALT lymphomas with the final goal to dissect the clinicopathologic heterogeneity of these disorders and design more tailored preventive and therapeutic approaches.

Outcome of radiotherapy for gastric mucosa-associated lymphoid tissue lymphoma refractory to Helicobacter pylori eradication therapy

BACKGROUNDS AND AIMS

Most low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphomas respond to eradication of H. pylori, however, some are refractory. The effectiveness of radiotherapy for MALT lymphoma refractory to H. pylori eradication has been demonstrated. However, the long-term outcome and associated late radiation morbidity of radiotherapy for gastric MALT lymphoma are unclear. We evaluated the efficacy of radiotherapy and the radiation-associated adverse effects for gastric MALT lymphoma refractory to H. pylori eradication therapy.

METHODS

Eighteen patients with H. pylori-positive gastric MALT lymphoma received H. pylori eradication therapy, of which three patients refractory to eradication of H. pylori were subsequently treated with irradiation (median 39 Gy, range 36-40 Gy). Efficacy of radiotherapy and associated radiation morbidity were evaluated. Adverse events were evaluated according to RTOG and NCI-CTC criteria.

RESULTS

Radiation was well tolerated. All three patients treated with radiotherapy achieved complete remission, which was sustained for a median follow-up period of 42.0 months (range, 24-72 months). As acute radiation side effects, all patients experienced mild nausea (Grade 1 by RTOG and 1 point [1 category] in NCI-CTC). One patient had Grade 1 appetite loss. There were no severe late adverse events. One patient had left kidney atrophy of approximately 10%, but none had renal dysfunction.

CONCLUSIONS

Radiotherapy for patients with gastric MALT lymphoma refractory to H pylori eradication was effective without any critical acute or late adverse events.

Limited Gastric Resection

Despite recent advancements in the staging and treatment of gastric cancer, overall survival remains poor. Extended or radical resections, to include the entire stomach, regional lymph nodes,or contiguous organs, have thus been proposed to alter the course of this fatal disease; however, no prospective randomized trial has validated this approach in a Western center. Furthermore, there are other malignant tumors that occur in the stomach and that may be successfully treated with a limited, nonanatomic, or subtotal gastrectomy, or in the case of gastric lymphoma, without surgery at all. Palliative approaches to patients who have advanced gastric cancer, which should be conservative by nature, are also outlined.

Mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach: results of a controlled clinical trial

Treatment of patients with early stage gastric mucosa-associated lymphoid tissue (MALT) remains undefined. We began a controlled clinical trial to evaluate efficacy and toxicity of the most common therapies. Two hundred and forty-one patients with gastric low-grade MALT lymphoma in early stage (IE and IIE) were randomized to surgery (80 cases), radiotherapy (78 cases), and chemotherapy (83 cases). With a median follow-up of 7.5 yr, actuarial curves at 10 yr showed that event-free survival was 52% in patients treated with surgery, 52% in radiotherapy arm, and 87% in the chemotherapy group (p < 0.01). However, overall survival did not showed any statistical differences: 80%, 75% and 87%, respectively (p = 0.4). Acute and late toxicities were mild. No death-related treatments were observed. No clear differences were observed between the most common therapies in patients with primary gastric MALT lymphoma in early stages, probably because this type of lymphoma has an high response rate to salvage treatment after failure to local treatment (surgery and radiotherapy). Thus considered, chemotherapy alone is an effective and safe therapeutic approach in this setting of patients. Surgery or radiotherapy will be reserved to patients that are not candidates for chemotherapy.

Mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach: results of a controlled clinical trial

Treatment of patients with early stage gastric mucosa-associated lymphoid tissue (MALT) remains undefined. We began a controlled clinical trial to evaluate efficacy and toxicity of the most common therapies. Two hundred and forty-one patients with gastric low-grade MALT lymphoma in early stage (IE and IIE) were randomized to surgery (80 cases), radiotherapy (78 cases), and chemotherapy (83 cases). With a median follow-up of 7.5 yr, actuarial curves at 10 yr showed that event-free survival was 52% in patients treated with surgery, 52% in radiotherapy arm, and 87% in the chemotherapy group (p < 0.01). However, overall survival did not showed any statistical differences: 80%, 75% and 87%, respectively (p = 0.4). Acute and late toxicities were mild. No death-related treatments were observed. No clear differences were observed between the most common therapies in patients with primary gastric MALT lymphoma in early stages, probably because this type of lymphoma has an high response rate to salvage treatment after failure to local treatment (surgery and radiotherapy). Thus considered, chemotherapy alone is an effective and safe therapeutic approach in this setting of patients. Surgery or radiotherapy will be reserved to patients that are not candidates for chemotherapy.

Mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach: results of a controlled clinical trial

Treatment of patients with early stage gastric mucosa-associated lymphoid tissue (MALT) remains undefined. We began a controlled clinical trial to evaluate efficacy and toxicity of the most common therapies. Two hundred and forty-one patients with gastric low-grade MALT lymphoma in early stage (IE and IIE) were randomized to surgery (80 cases), radiotherapy (78 cases), and chemotherapy (83 cases). With a median follow-up of 7.5 yr, actuarial curves at 10 yr showed that event-free survival was 52% in patients treated with surgery, 52% in radiotherapy arm, and 87% in the chemotherapy group (p < 0.01). However, overall survival did not showed any statistical differences: 80%, 75% and 87%, respectively (p = 0.4). Acute and late toxicities were mild. No death-related treatments were observed. No clear differences were observed between the most common therapies in patients with primary gastric MALT lymphoma in early stages, probably because this type of lymphoma has an high response rate to salvage treatment after failure to local treatment (surgery and radiotherapy). Thus considered, chemotherapy alone is an effective and safe therapeutic approach in this setting of patients. Surgery or radiotherapy will be reserved to patients that are not candidates for chemotherapy.

Radiation treatment planning techniques for lymphoma of the stomach

PURPOSE

Involved-field radiation therapy of the stomach is often used in the curative treatment of gastric lymphoma. Yet, the optimal technique to irradiate the stomach with minimal morbidity has not been well established. This study was designed to evaluate treatment planning alternatives for stomach irradiation, including intensity-modulated radiation therapy (IMRT), to determine which approach resulted in improved dose distribution and to identify patient-specific anatomic factors that might influence a treatment planning choice.

METHODS AND MATERIALS

Fifteen patients with lymphoma of the stomach (14 mucosa-associated lymphoid tissue lymphomas and 1 diffuse large B-cell lymphoma) were categorized into 3 types, depending on the geometric relationship between the planning target volume (PTV) and kidneys. AP/PA and 3D conformal radiation therapy (3DCRT) plans were generated for each patient. IMRT was planned for 4 patients with challenging geometric relationship between the PTV and the kidneys to determine whether it was advantageous to use IMRT.

RESULTS

For type I patients (no overlap between PTV and kidneys), there was essentially no benefit from using 3DCRT over AP/PA. However, for patients with PTVs in close proximity to the kidneys (type II) or with high degree of overlap (type III), the 4-field 3DCRT plans were superior, reducing the kidney V(15 Gy) by approximately 90% for type II and 50% for type III patients. For type III, the use of a 3DCRT plan rather than an AP/PA plan decreased the V(15 Gy) by approximately 65% for the right kidney and 45% for the left kidney. In the selected cases, IMRT led to a further decrease in left kidney dose as well as in mean liver dose.

CONCLUSIONS

The geometric relationship between the target and kidneys has a significant impact on the selection of the optimum beam arrangement. Using 4-field 3DCRT markedly decreases the kidney dose. The addition of IMRT led to further incremental improvements in the left kidney and liver dose in selected patients.

Gastric mucosa-associated lymphoid tissue lymphoma and Helicobacter pylori: scratch and win

Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is generally associated with Helicobacter pylori infection and, in the great majority of patients, regresses after eradication. H. pylori-negative MALT lymphoma occurs in a small minority of cases in which treatment is based on surgery or chemoradiotherapy. In the search for H. pylori based on histology and the C13 urea breath test, this report describes a case with a series of false-negative results, thus confirming the possibility of a lower detectability of H. pylori in patients with MALT gastric lymphoma and supporting the use of additional tests in evaluating such pathology, including polymerase chain reaction. Additionally, treatment with CD20 monoclonal antibody (rituximab) is suggested as an alternative to surgery or treatment with chemotherapy or radiotherapy in patients with truly H. pylori-negative gastric MALT lymphoma.

Treatment of extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) with mitoxantrone, chlorambucil and prednisone (MCP)

BACKGROUND

Mucosa-associated lymphoid tissue (MALT) lymphoma is a relatively common type of lymphoma arising in various tissues throughout the human body. Currently, there is no standard chemotherapy for advanced stage MALT lymphoma. This has prompted us to retrospectively analyse our experience with the MCP regimen (mitoxantrone, chlorambucil and prednisone) in patients with MALT lymphoma.

PATIENTS AND METHODS

Patients with histologically verified MALT lymphoma undergoing chemotherapy with MCP were evaluated retrospectively. The MCP regimen consists of mitoxantrone 8 mg/m(2) intravenously on days 1 and 2, chlorambucil 3 x 3 mg/m(2) per os (p.o.) on days 1-5 and prednisone 25 mg/m(2) p.o. on days 1-5. Information analysed included localisation of the lymphoma, clinical stage, pretreatment, number of chemotherapy cycles administered, toxicity, response to treatment, follow-up time, relapse and survival.

RESULTS

A total of 15 patients (six females and nine males aged between 34 and 88 years) with histologically ascertained MALT lymphoma undergoing treatment with the MCP regimen were identified from our records. Ten patients had extragastric lymphoma, while five patients suffered from gastric MALT lymphoma. All patients were chemotherapy-naïve, while two had been locally irradiated before application of MCP for recurrent disease. A total of 74 cycles was administered to our patients, with a median number of five cycles per patient. Eight (53%) patients achieved complete remission, six (40%) patients partial response and only one (7%) patient had progressive disease. Subjective tolerance was excellent, and toxicities were mainly haematological, including granulocytopenia World Health Organisation grade 3 and 4 in three patients each. In two patients, this was accompanied by single episodes of uncomplicated herpes simplex infection. At the time of analysis, all patients are still alive. No relapses have occurred after a median follow-up time of 16 (range 12-29) months.

CONCLUSIONS

Our data suggest that MCP is an effective and well-tolerated regimen for treatment of patients with MALT lymphoma irrespective of localisation. Judging from our data, MCP also appears to be a feasible regimen in elderly patients.

Rationale for radiotherapy as a treatment modality in gastric mucosa-associated lymphoid tissue lymphoma

PURPOSE

To provide a rationale for the use of local radiotherapy (RT) for the treatment of low-grade mucosa-associated lymphoid tissue lymphoma of the stomach (MLS). In addition, the clinicopathologic characteristics were analyzed.

METHODS AND MATERIALS

The data of 72 patients with MLS, who underwent radical surgery between 1991 and 2001, were retrospectively reviewed. The depth of invasion into the gastric wall and the pattern of lymph node spread according to pathologic grade were analyzed.

RESULTS

The patient age range was 24-77 years (median, 51 years). Of the 72 patients, 45 (62.5%) had low-grade and 27 (37.5%) had high-grade MLS; 44 (61%) had Stage I and 28 (39%) Stage II. The tumors were confined to the mucosa or submucosa in 43 patients (58.9%). Sixty-seven percent of low-grade tumors and 48% of high-grade tumors were confined to the mucosa and submucosa. Lymph node involvement was identified in 24.4% of the low-grade MLS patients and 63.0% of the high-grade MLS patients. In the low-grade group, lymph node involvement was limited to the perigastric lymph nodes in all cases except for one. One patient with tumor infiltration beyond the serosa had extensive lymph node involvement into the paraaortic and omental lymph nodes.

CONCLUSION

Local RT to the stomach and regional lymphatics can be applied preferably instead of gastrectomy in patients with low-grade MLS who are negative for Helicobacter pylori or are refractory to anti-H. pylori therapy. The timing of RT and the exclusion criteria for RT should be determined in the future.

Primary gastrointestinal non-Hodgkin's lymphoma: treatment outcome

Primary gastrointestinal lymphoma is the most common extranodal presentation of non-Hodgkin's lymphoma. In this retrospective study, all cases of primary gastrointestinal lymphoma registered at Kuwait Cancer Control Center between January 1992 and December 2001 were reviewed. Patients were diagnosed through an endoscopic biopsy or exploratory laparotomy. Staging procedures included computed axial tomography scan, bone marrow biopsy, barium and follow-through study, as well as routine chemistry (including lactate dehydrogenase) and hemography. There were 46 patients (30 men and 16 women); ages ranged from 16 to 82 years (median age, 43.6 years). The most common site of involvement was the stomach (70%), and the most common histology was large B cell. At least 50% of cases underwent primary radical surgery, and the majority of patients received subsequent chemotherapy and/or local radiation therapy. Chemotherapy consisted of the CHOP (cyclophosphamide/doxorubicin/vincristine/prednisone) regimen for large B-cell histology and CVP (cyclophosphamide/vincristine/prednisone) or oral alkylating agents for low-grade histology. Of this cohort, only 12 cases (26%) have had local or distant relapse. Disease-free survival rates for low-grade and high-grade non-Hodgkin's lymphoma were 64% and 81%, respectively. Primary gastrointestinal lymphoma is a potentially curable malignancy.

Localized mucosa-associated lymphoid tissue lymphoma treated with radiation therapy has excellent clinical outcome

PURPOSE

Extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) is a distinct lymphoma with unique clinicopathologic features. We report the clinical outcome of stage I and II MALT lymphoma treated with involved field radiation therapy (RT).

PATIENTS AND METHODS

From 1989 to 2000, 103 patients with stage IE and IIE disease were referred. Their median age was 60 years, with a 2:1 female predominance. Presenting sites were stomach (17 patients), orbital adnexa (31 patients), salivary glands (24 patients), thyroid gland (13 patients), and other sites (18 patients). Ninety-three patients received RT--85 received RT alone, and eight received chemotherapy and RT--with a median dose of 30 Gy. The median follow-up time was 5.1 years.

RESULTS

A complete response (CR) to RT alone was achieved in 84 of 85 patients. Among CR patients, 14 experienced relapse. Relapse sites were mostly contralateral paired-organ or distant MALT locations and, infrequently, lymph nodes. The crude local control rate with RT was 95.3% (81 of 85 patients). No relapses were observed in patients with stomach or thyroid lymphoma, whereas 14 of 63 patients (22%) experienced relapse in the other sites. The overall 5-year survival rate was 98%, and the disease-free survival rate was 77%. Transformed lymphoma was observed in 14% of patients (two of 14) experiencing relapse.

CONCLUSION

Moderate-dose RT achieved excellent local control in localized MALT lymphomas and had curative potential for three fourths of the patients. Gastric and thyroid MALT lymphomas had better outcome, whereas distant failures were common for other sites. Despite relapse, the disease often maintained an indolent course.

Gastrointestinal lymphoma

The ability to make treatment recommendations for patients with gastrointestinal lymphoma is hampered by a lack of prospective trials and by a lack of uniformity in classification and staging. Patients with gastric diffuse large B-cell lymphoma have traditionally been treated with surgery and many physicians continue to recommend this approach. However, recent data suggest that these patients can be treated with combination chemotherapy regimens in the same manner as patients with nodal presentations of diffuse large B-cell lymphoma. There is evidence to suggest that adjuvant radiotherapy may improve the outcome for these patients. The recognition that extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue is a distinct clinicopathologic entity and the elucidation of the pathogenic role of Helicobacter pylori has revolutionized the treatment of these gastric lymphomas. Patients with localized disease should be managed with antibiotic therapy initially. Radiation therapy is extremely effective for these patients, but it should probably be reserved for patients who fail anti-H. pylori treatment.

A case of mucosa-associated lymphoid tissue lymphoma of the ampulla of Vater: successful treatment with radiation therapy

Mucosa-associated lymphoid tissue (MALT) lymphoma of the papilla of Vater is rare, and little is known of either its association with Helicobacter pylori infection or the optimal treatment modalities. We describe the first case of MALT lymphoma involving the major papilla that remained unchanged despite eradication of H. pylori, but which regressed following radiotherapy. A 46-year-old asymptomatic man was admitted to hospital for treatment of MALT lymphoma involving the papilla of Vater. Duodenal endoscopy showed multiple granules around the major ampulla, and biopsies revealed mucosal proliferation of centrocyte-like cells, lymphoepithelial lesions, hyperplastic lymphoid follicles and plasmacytic differentiation. The lymphoma cells were positive for B-cell but negative for T-cell markers, and expressed Bcl-2 but showed no immunoreactivity for CD5, CD10 and cyclin D, consistent with MALT lymphoma. The patient was successfully treated with triple therapy of lansoprazole, amoxicillin and clarithromycin for 1 week for coexisting H. pylori infection in the stomach, but the lymphoma lesions remained unchanged. Then, involved-field irradiation was applied at a total dose of 30 Gy delivered in 1.5 Gy fractions without any adverse events. Six months later, repeat endoscopy revealed disappearance of the granular lesions and lack of lymphoma cells in biopsy specimens. Four years after the commencement of radiotherapy, the patient is still in complete remission. Radiotherapy seems a safe and effective treatment modality for low-grade MALT lymphoma of the ampulla of Vater.

Update: gastric MALT lymphoma

PURPOSE OF REVIEW

Gastric MALT lymphoma is a model malignancy for examination of how neoplasia may arise from chronic inflammation. It is also exemplifies the translation of biologic knowledge of a disease towards improved clinical practice. Several recent publications have furthered the understanding of gastric MALT lymphoma pathogenesis, clinical behavior, and treatment.

RECENT FINDINGS

A substantial fraction of cases will harbor a balanced translocation between chromosomes 11 and 18. This translocation results in the generation of a novel fusion protein, aberrant nuclear BCL10 expression, and activation of the NF-kB pathway. The result is H. pylori-independent growth and a unique clinical picture characterized by a more advanced presentation and unresponsiveness to H. pylori eradication therapy. While more likely to require cytotoxic therapy, this subtype is paradoxically less likely to undergo large-cell transformation. Finally, clinical trials are helping define the optimal role for H. pylori eradication therapy and are demonstrating that therapeutic approaches incorporating stomach conservation are preferable for those cases unresponsive to eradication therapy.

SUMMARY

The pathogenesis of gastric MALT lymphoma has been elucidated to a large degree in recent years. Understanding the biology of this disease will most certainly translate into clinical practice.