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

Radiation Therapy Dose for Limited-stage Extranodal Marginal Zone Lymphomas of the Mucosa-associated Lymphoid Tissues of the Stomach: A Meta-analysis

PURPOSE

To compare the outcomes of 2 standard radiation therapy (RT) doses for limited-stage gastric extranodal marginal zone lymphoma (EMZL) of the mucosa-associated lymphoid tissues.

METHODS AND MATERIALS

A database search was performed to identify articles published from database inception to August 31, 2023. Based on the current standard dose of 24.0 to 30.0 Gy, doses of approximately 30.0 Gy were classified as standard dose (SD), while those of approximately 24.0 Gy were classified as low dose (LD). Pooled estimates of the complete remission (CR) and local recurrence (LR) rates were calculated and compared.

RESULTS

Data from 1072 patients across 30 included studies were analyzed. SD was used in 28 studies (n = 987), while LD was used in 6 studies (n = 85), and both regimens were used in 4 studies. In all included studies, the CR rate was 0.96 (95% CI, 0.94-0.97), and the LR rate was 0.05 (95% CI, 0.04-0.06), showing no significant between-study heterogeneity (τ2 = 0 and I2 = 0% for both; P = .8447 and .9998, respectively). SD and LD resulted in no significant differences in the CR rates (0.96 [95% CI, 0.94-0.97] vs 0.96 [95% CI, 0.89-0.99]; P = .9174) or LR rates (0.05 [95% CI, 0.04-0.06] vs 0.03 [95% CI, 0.01-0.10]; P = .5495).

CONCLUSIONS

Both the SD and LD groups achieved excellent CR and LR rates. These results indicate that the RT dose for limited-stage gastric EMZL may be safely de-escalated without compromising local tumor control.

Nomogram model predicting the overall survival for patients with primary gastric mucosa-associated lymphoid tissue lymphoma

BACKGROUND

Increasingly extranodal marginal B-cell lymphoma of mucosa-associated lymphoid tissue, known as mucosa-associated lymphoid tissue (MALT) lymphoma, is a type of non-Hodgkin’s lymphoma. The prognosis of primary gastric MALT (GML) patients can be affected by many factors. Clinical risk factors, including age, type of therapy, sex, stage and family hematologic malignancy history, also have significant effects on the development of the disease. The available data are mainly focused on epidemiology; in contrast, few studies have investigated the prognostic variables for overall survival (OS) in patients with primary GML. Based on the realities above, we searched a large amount of data on patients diagnosed with primary GML in the Surveillance, Epidemiology and End Results (SEER) database. The aim was to develop and verify a survival nomogram model that can predict the overall survival prognosis of primary GML by combining prognostic and determinant variables.

AIM

To create an effective survival nomogram for patients with primary gastric GML.

METHODS

All data of patients with primary GML from 2004 to 2015 were collected from the SEER database. The primary endpoint was OS. Based on the LASSO and COX regression, we created and further verified the accuracy and effectiveness of the survival nomogram model by the concordance index (C-index), calibration curve and time-dependent receiver operating characteristic (td-ROC) curves.

RESULTS

A total of 2604 patients diagnosed with primary GML were selected for this study. A total of 1823 and 781 people were randomly distributed into the training and testing sets at a ratio of 7:3. The median follow-up of all patients was 71 mo, and the 3- and 5-year OS rates were 87.2% and 79.8%, respectively. Age, sex, race, Ann Arbor stage and radiation were independent risk factors for OS of primary GML (all P < 0.05). The C-index values of the nomogram were 0.751 (95%CI: 0.729-0.773) and 0.718 (95%CI: 0.680-0.757) in the training and testing cohorts, respectively, showing the good discrimination ability of the nomogram model. Td-ROC curves and calibration plots also indicated satisfactory predictive power and good agreement of the model. Overall, the nomogram shows favorable performance in discriminating and predicting the OS of patients with primary GML.

CONCLUSION

A nomogram was developed and validated to have good survival predictive performance based on five clinical independent risk factors for OS for patients with primary GML. Nomograms are a low-cost and convenient clinical tool in assessing individualized prognosis and treatment for patients with primary GML.

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).

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.

Gastric MALT-Lymphoma: more than Helicobacter Pylori

In this case report, we describe two cases of gastric mucosaassociated lymphoid tissue (MALT) lymphoma. The first patient, who presented with complaints of indigestion, nausea and epigastralgy, had a solid ulcer on endoscopy. Biopsies showed, next to MALT, presence of Helicobacter Pylori. The second patient was admitted with hematemesis. The multiple ulcerations in his stomach were thought to be cocaine-induced. Only after multiple biopsies the diagnosis of MALT was made. No presence of Helicobacter Pylori could be detected. The first patient was successfully treated with Helicobacter Pylori eradication therapy. Localized radiotherapy resulted in complete remission in our second patient. Hence, in absence of Helicobacter Pylori, more aggressive treatment modalities are needed.

Prospective Phase II trial of radiation therapy in localised non-gastric marginal zone lymphoma with prospective evaluation of autoimmunity and Helicobacter pylori status: TROG 05.02/ALLG NHL15

BACKGROUND

This Phase 2 multicentre trial in localised non-gastric marginal zone lymphoma (MZL) evaluated the effectiveness and safety of radiotherapy and documented markers of autoimmunity and Helicobacter pylori infection.

PATIENTS AND METHODS

Eligible patients had Stages I and II or paired-organ, non-gastric MZL. Bone marrow evaluation, autoantibody panel, and H. pylori evaluation were mandatory. Involved-field or involved-site radiotherapy was delivered to 24-30.6 Gy. Detected H. pylori infections underwent eradication.

RESULTS

Between 2006 and 2014, six centres enrolled 70 patients, and 68 commenced treatment. The median age was 59 (range: 23-84) years, and 31 (46%) were male. Overall, 55 patients had Stage I disease, nine patients had Stage II disease, and four patients had paired organ-confined disease. Involved extranodal sites with three or more cases were orbital (n = 18), conjunctiva (n = 13), lacrimal (n = 8), skin (n = 8), salivary (n = 7), and muscle (n = 4). Eight patients had primary nodal MZL. At the median follow-up of 5 years (range 0.7-9.4), progression-free survival and overall survival were 79% and 95%, respectively. One lymphoma-related death and two in-field failures (after 25 and 30 Gy, respectively) occurred. Distant relapse sites were skin (n = 2), lymph nodes (n = 2), duodenum, stomach, muscle, and conjunctiva (1 each). No paired-organ MZL relapsed. Apart from cataracts (n = 18), only three treatment-related late grade ≥3 adverse events occurred. Autoantibodies or autoimmune events were detected in 26 of 68 patients (38%). H. pylori infection was detected in 15 of 63 patients (24%) tested. Neither autoimmunity nor H. pylori was detected in 27 of 68 patients (40%).

CONCLUSIONS

Radiotherapy was a potentially curative treatment with low toxicity in localised non-gastric MZL. Autoimmunity, H. pylori infection or both were detected in 60% of patients.

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

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

Sequential H. pylori eradication and radiation therapy with reduced dose compared to standard dose for gastric MALT lymphoma stages IE & II1E: a prospective randomized trial

BACKGROUND

In Helicobacter pylori (H. pylori) positive stage I gastric low-grade MALT lymphoma, eradication is the accepted first-line therapy. The role of eradication therapy in lymphoma > stage IE is still unclear. However, about 20% of patients show persistent lymphoma following successful eradication or primary H. pylori-negative lymphoma. A prospective study for salvage radiation therapy with standard 36 Gy in comparison to a reduced dose of 25.2 Gy is still missing.

METHODS

A prospective, multicentre study investigated the efficacy of eradication in H. pylori-positive gastric low-grade MALT lymphoma stages IE and II1E (HELYX I). Refractory lymphoma or H. pylori-negative patients were treated in a prospective, randomised, multicentre, phase II study to receive either 25.2 Gy or 36 Gy radiotherapy (HELYX II).

RESULTS

102 patients (3 drop outs) were included in HELYX I: 75/99 (75.8%) showed complete remission after a median of 2.8 months. 18 (18.2%) had partial remission (PR) and 6 (6.0%) no change (NC). 29 patients (7 drop outs) were randomized in HELYX II (7 primarily H. pylori-negative, 15 patients from HELYX I with refractory disease after eradication). All patients achieved stable CR irrespective of radiation dose. Both presence of the t(11,18) translocation (OR 9.0, p = 0.01) and monoclonality of the tumour cells (OR 6.3, p = 0.006) were predictors for persistant lymphoma after eradication therapy.

CONCLUSIONS

Most H. pylori-positive low grade gastric MALT lymphoma stage IE and II1E respond with stable CR after eradication therapy. In patients with refractory disease or H. pylori negative low grade gastric MALT lymphoma a dosage-reduced radiation therapy with 25.2 Gy is an effective standard dose in stage IE and II1E.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00154440.

Outcomes After Reduced-Dose Intensity Modulated Radiation Therapy for Gastric Mucosa-Associated Lymphoid Tissue (MALT) Lymphoma

PURPOSE

In patients with gastric extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) lymphoma, the standard radiation therapy (RT) dose is ≥30 Gy. We report the outcome of patients treated with reduced dose 24 Gy compared with those treated with ≥30 Gy.

METHODS AND MATERIALS

We reviewed results from 32 patients who received a diagnosis of gastric MALT lymphoma between 2007 and 2017 who were treated with involved site RT using intensity modulated radiation therapy (IMRT). Response to therapy was based on post-RT endoscopic biopsy. Freedom from local treatment failure (FFLTF), freedom from treatment failure (FFTF), and overall survival (OS) outcomes were determined.

RESULTS

The median age of patients at diagnosis was 58 years. Therapy for MALT was given prior to RT in 14 patients with residual biopsy proven disease documented in all cases (anti-microbial, n=11; rituximab, n=2; rituximab, cyclophosphamide, doxorubicin, vincristine, n=1). One patient received RT (36 Gy) and concurrent rituximab. The median RT dose was 30 Gy; it was 30 to 36 Gy in 66% of patients (n = 21) and 24 Gy in 34% of patients (n = 11). Post-RT biopsy documented a complete response in all patients. Failures occurred in the stomach and duodenum, respectively, at 3.6 and 4.5 years, after 30 Gy. At a median follow-up of 55.2 months (73.8 for ≥30 Gy compared with 28.7 for 24 Gy; P < .001), the 2-year FFLTF, FFTF, and OS were 100%, 100%, and 97%, respectively. No association was found between the lower (24-Gy) dose and FFLTF (P = .819), FFTF (P = .819), or OS (P = .469).

CONCLUSIONS

Contemporary RT with involved site targeting using IMRT is associated with high complete response rates for patients with gastric MALT lymphoma, even using reduced doses of 24 Gy. Additional follow-up and increased patient numbers are required to confirm equivalent disease control.

[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.

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.

Radiotherapy for gastric mucosa-associated lymphoid tissue lymphoma: dosimetric comparison and risk assessment of solid secondary cancer

Purpose

To determine the optimal radiotherapy technique for gastric mucosa-associated lymphoid tissue lymphoma (MALToma), we compared the dosimetric parameters and the risk of solid secondary cancer from scattered doses among anterior-posterior/posterior-anterior parallel-opposed fields (AP/PA), anterior, posterior, right, and left lateral fields (4_field), 3-dimensional conformal radiotherapy (3D-CRT) using noncoplanar beams, and intensity-modulated radiotherapy composed of 7 coplanar beams (IMRT_co) and 7 coplanar and noncoplanar beams (IMRT_non).

Materials and Methods

We retrospectively generated 5 planning techniques for 5 patients with gastric MALToma. Homogeneity index (HI), conformity index (CI), and mean doses of the kidney and liver were calculated from the dose-volume histograms. Applied the Biological Effects of Ionizing Radiation VII report to scattered doses, the lifetime attributable risk (LAR) was calculated to estimate the risk of solid secondary cancer.

Results

The best value of CI was obtained with IMRT, although the HI varied among patients. The mean kidney dose was the highest with AP/PA, followed by 4_field, 3D-CRT, IMRT_co, and IMRT_non. On the other hand, the mean liver dose was the highest with 4_field and the lowest with AP/PA. Compared with 4_field, the LAR for 3D-CRT decreased except the lungs, and the LAR for IMRT_co and IMRT_non increased except the lungs. However, the absolute differences were much lower than <1%.

Conclusion

Tailored RT techniques seem to be beneficial because it could achieve adjacent organ sparing with very small and clinically irrelevant increase of secondary solid cancer risk compared to the conventional techniques.

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

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