The role of radiotherapy in the treatment of gastric mucosa-associated lymphoid tissue lymphoma

Clinical Management of Patients with Gastric MALT Lymphoma: A Gastroenterologist's Point of View

Gastric mucosa-associated lymphoid tissue (MALT) lymphomas (GML) are non-Hodgkin lymphomas arising from the marginal zone of the lymphoid tissue of the stomach. They are usually induced by chronic infection with Helicobacter pylori (H. pylori); however, H. pylori-negative GML is of increasing incidence. The diagnosis of GML is based on histological examination of gastric biopsies, but the role of upper endoscopy is crucial since it is the first step in the diagnostic process and, with currently available novel endoscopic techniques, may even allow an in vivo diagnosis of GML per se. The treatment of GML, which is usually localized, always includes the eradication of H. pylori, which should be performed even in H. pylori-negative GML. In the case of GML persistence after eradication of the bacteria, low-dose radiotherapy may be proposed, while systemic treatments (immunochemotherapy) should be reserved for very rare disseminated cases. In GML patients, at diagnosis but even after complete remission, special attention must be paid to an increased risk of gastric adenocarcinoma, especially in the presence of associated gastric precancerous lesions (gastric atrophy and gastric intestinal metaplasia), which requires adequate endoscopic surveillance of these patients.

Radiotherapy for gastric mucosa-associated lymphoid tissue lymphoma

Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is a rare disease which is often associated with Helicobacter pylori (H. pylori) infection. First-line treatment of stage IE and IIE localized gastric MALT lymphoma is based on the eradication of H. pylori. The presence of H. pylori resistance factors such as translocation t (11;18), peri-gastric lymph node involvement and the degree of tumor infiltration of the gastric wall; or lack of response to antibiotic therapy are two main indications to treat with definitive radiotherapy (RT). RT is an effective treatment in localized gastric MALT lymphoma. A moderate dose of 30 Gy allows a high cure rate while being well tolerated. After treatment, regular gastric endoscopic follow-up is necessary to detect a potential occurrence of gastric adenocarcinoma.

Development and validation of a prognostic nomogram for gastric marginal zone lymphoma: a Surveillance, Epidemiology and End Results-based population study

Aim: This initial study was conducted with the aim of constructing an accurate nomogram for gastric marginal zone lymphoma patients. Methods: Data from 4414 patients diagnosed with gastric mucosa-associated lymphoid tissue lymphoma from 2004 to 2015 were retrieved from the Surveillance, Epidemiology and End Results database. Multivariate analyses were conducted for the construction of the nomogram. Results: Age, sex, race, marital status, Ann Arbor stage and radiotherapy were significantly associated with overall survival, while age, marital status, Ann Arbor stage, surgery, chemotherapy and radiotherapy were independent prognostic predictors of cause-specific survival. Stratified analysis indicated that radiotherapy alone resulted in better overall survival and cause-specific survival than chemotherapy alone. However, the present study also has several limitations; for example, patients' Helicobacter pylori infection status and the chemotherapy regimen used were unknown. Conclusion: This study constructed and validated an accurate prognostic nomogram for gastric mucosa-associated lymphoid tissue lymphoma patients.

Second Cancers in a Patient with Gastric MALT Lymphoma

Mucosa-associated lymphoid tissue (MALT) lymphoma is an extranodal low-grade B-cell lymphoma, which is thought to arise from a background of chronic immune stimulation, bacterial, viral, or autoimmune stimuli. Treatment advances have increased the number of MALT lymphoma survivors, but there is still debate as to whether these patients are at a higher risk of developing second cancers. This is a case of a long-surviving (>20 years) patient with multiple diagnosed malignancies following MALT lymphoma. We describe how modern oncological treatment plans can provide patients with prolonged survival and increased quality of life despite increasing age and multiple malignancies.

Favorable radiation field decrease in gastric marginal zone lymphoma : Experience of the German Study Group on Gastrointestinal Lymphoma (DSGL)

PURPOSE

Long-term impact of stage-adapted field reduction in a large cohort of gastric marginal zone lymphoma (gMZL) patients treated conservatively with curative radiation therapy (RT).

PATIENTS AND METHODS

Prospective analysis of paper records of 290 patients with stage IE-IIE gMZL, treated in 78 radiotherapeutic institutions in Germany from 1992-2013. Stage-adapted radiation fields decreased from extended field (EF) to involved field (IF) over the course of three consecutive prospective trials of the German Study Group on Gastrointestinal Lymphoma (DSGL). Treatment results were compared between the three cohorts.

RESULTS

Overall collective with median age of 60 years, slight male predominance (m:f = 1.1:1) and ratio of disease stage I:stage II = 2.1:1. Median follow-up 6.4 years in total: 13.0 years in the first gastrointestinal study (GIT 1992), 8.2 years in the second (GIT 1996) and 4.7 years in the third study (DSGL 01/2003). Stage-adapted radiation field decrease together with further technological development led to reduced relative frequencies of acute/chronic adverse effects and until now was accompanied by lower disease recurrence. The third study design with smallest field size (IF in stage I, locoregional EF in stage II) achieved the best survival outcome at the 5‑year follow-up (overall survival 92.7%, event-free survival 89.5% and lymphoma-specific survival 100.0%). Disease relapse observed in 10 patients. Cumulative incidence of disease-specific death was 1.7% of the followed patients. Primary disease stage associated with lymphoma-specific survival.

CONCLUSION

Stage-adapted reduction towards IF in gMZL resulted in favorable adverse effects, local control and survival rates. These results support further decreases in modern RT of gMZL.

[Results of a retrospective study on radiotherapy for gastric mucosa-associated lymphoid tissue lymphoma]

PURPOSE

We aimed to evaluate therapeutic results of radiotherapy for gastric mucosa-associated lymphoid tissue (MALT) lymphomas.

PATIENTS AND METHODS

We reviewed retrospectively the records of 11 patients presenting with gastric MALT lymphoma treated between 1993 and 2014. Patients with low-grade lymphoma in failure after helicobacter eradication had exclusive gastric external radiotherapy. Chemotherapy followed by radiotherapy were indicated in case of high grade lymphoma. Radiotherapy doses range between 30 and 40Gy (2Gy per fraction, five fractions per week).

RESULTS

All tumours were IE stage. Seven patients with low-grade lymphoma had radiotherapy. Four patients with high-grade lymphoma received chemotherapy then radiotherapy. Ten patients are in complete remission after treatment achievement. Five and 10 years disease-free survival are 100%. No severe toxicity was seen.

CONCLUSION

Eradication of Helicobacter pylori is the mainstay of treatment of gastric MALT. External irradiation is an effective and well-tolerated treatment modality in case of resistance to helicobacter eradication.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Long-term course of precancerous lesions arising in patients with gastric MALT lymphoma

BACKGROUND AND AIMS

To evaluate the prevalence and the long-term course of gastric precancerous lesions in patients with GML.

PATIENTS AND METHODS

In this retrospective single-centre study, we included 179 patients with GML, 70 with gastric diffuse large B-cell lymphoma (GDLBCL) and 152 with Helicobacter pylori-associated gastritis (HpG), from January 1995 to January 2014. The presence of atrophic gastritis, intestinal metaplasia and neoplastic lesion has been assessed at baseline and during follow-up.

RESULTS

Atrophic gastritis was more frequent in the GML group whereas there was also a trend for intestinal metaplasia and gastric dysplasia. In patients with GML, atrophic gastritis, intestinal metaplasia and gastric dysplasia were more frequent in the GML area than in other part of the stomach. During follow-up, the prevalence of atrophic gastritis remained stable overtime whereas intestinal metaplasia and dysplasia tend to increase overtime. In multivariate analysis, the occurrence of dysplasia or carcinoma was associated with the presence of intestinal metaplasia at baseline and male gender.

CONCLUSION

GML is associated with gastric precancerous lesion to a higher extent than GDLBCL and HpG. Those precancerous lesions do not regress despite achievement of complete remission of GML and tend to increase overtime.

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.

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

Purpose

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

Materials and Methods

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

Results

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

Conclusion

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

Differential somatostatin and CXCR4 chemokine receptor expression in MALT-type lymphoma of gastric and extragastric origin

PURPOSE

Whereas the different somatostatin receptor (SSTR) subtypes and the chemokine receptor CXCR4 are known to be expressed in a wide variety of human malignancies, comprehensive data are still lacking for MALT-type lymphomas.

METHODS

Overall, 55 cases of MALT-type lymphoma of both gastric and extragastric origin were evaluated for the SSTR subtype and CXCR4 expression by means of immunohistochemistry using novel monoclonal rabbit antibodies. The stainings were rated by means of the immunoreactive score and correlated with clinical data.

RESULTS

While the CXCR4 was detected in 92 % of the cases investigated, the SSTR subtypes were much less frequently present. The SSTR5 was expressed in about 50 % of the cases, followed by the SSTR3, the SSTR2A, the SSTR4 and the SSTR1, which were present in 35, 27, 18 or 2 %, respectively, of the tumors only. Gastric lymphomas displayed a significantly higher SSTR3, SSTR4 and SSTR5 expression than extragastric tumors. A correlation between CXCR4 and Ki-67 expression was seen in gastric lymphomas, whereas primarily in extragastric tumors SSTR5 negativity was associated with poor patient outcome.

CONCLUSIONS

The CXCR4 may serve as a promising target for diagnostics and therapy of MALT-type lymphomas, while the SSTRs appear not suitable in this respect.

Refractory peptic ulceration following radiation therapy in primary gastric lymphoma: A report of two cases

The optimal prognosis for primary gastric lymphoma (PGL) is observed in those patients exhibiting PGL with minimal infiltration and who are eligible for radical resection. The initial treatment strategy for high-grade PGL (stages I/II) is chemotherapy followed by radiotherapy, however, subsequent to chemotherapy and/or radiotherapy for PGL, there is a risk of gastric bleeding and perforation. The present study reports two cases of PGL with refractory peptic ulcers that were negative for Helicobacter pylori following radiotherapy. Although the two patients received regular treatment for their ulcers and symptoms, the position and size of the ulcers remained unchanged for a number of years.