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.

Primary Gastrointestinal Follicular Lymphomas: A Prospective Study of 31 Patients with Long-term Follow-up Registered in the French Gastrointestinal Lymphoma Study Group (GELD) of the French Federation of Digestive Oncology (FFCD).

BACKGROUND/AIMS: Primary gastrointestinal follicular lymphomas (PGFL) are very rare. Our aim was to analyze the clinical features, management, and long-term outcomes in a prospective series of patients diagnosed with PGFL. METHODS: All adult patients with PGFL, consecutively enrolled into the multicenter French study between 1990 and 2017, were evaluated and followed up prospectively after undergoing a complete work-up. Clinical, pathological and endoscopic features, as well as treatment outcomes, were analyzed. RESULTS: Thirty-one patients (16 men, median age 62 years, range 33 to 79 years) with PGFL were included. The median follow-up was 92 months (range, 6 to 218 months). In the majority of patients (n=14), lymphoma was incidentally diagnosed during endoscopy. Otherwise, the most frequent circumstances of diagnosis were abdominal pain (n=7) and dyspepsia (n=5). The duodenum was the most common site of involvement (n=19) and multifocal localizations were seen in seven patients (22%). The most frequent first line strategy was surveillance applied in 22 patients (71%), of whom nine reached spontaneous, complete remission and 11 had stable disease. Seven patients (23%) received chemotherapy as first line treatment, and two underwent resection. Of seven patients who received chemotherapy, four achieved complete remission. In three patients, transformation into a high-grade lymphoma occurred. CONCLUSIONS: The diagnosis of PGFL is frequently fortuitous. The most common localization is in the duodenum. The disease has an indolent course and a good prognosis, however, rare cases of transformation into aggressive high-grade lymphoma may occur. An appropriate characterization and follow-up of these lymphomas is mandatory for their optimal management.

Gastric MALT lymphoma in a population-based study in France: clinical features, treatments and survival.

BACKGROUND: Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is a rare disease, and most available data on gastric MALT lymphoma (GML) come from clinical studies of selected patients treated in centres of excellence. AIMS: To analyse the clinical features, management and survival of GML patients in a population-based study in France METHODS: All new cases of GML diagnosed between 2002 and 2010 in 11 French areas covered by cancer registries were included. Pathology reports were verified and, if necessary, reviewed by an expert pathologist. All clinical data were retrospectively collected from medical files and analysed using stata V. 14 software. RESULTS: Four hundred and sixteen patients with confirmed GML (50% male, median age 67 years) were identified. Among them, 44 showed an early transformation into diffuse large B cell lymphoma and were considered to have had an initially missed high-grade lymphoma. At diagnosis, 76% of patients were at stage IE/II, and 24% at stage III/IV of the disease. Helicobacter pylori infection was found in 57% of the patients. Eradication treatment was administered to 76% of patients and complete remission (CR) was obtained in 39%. One hundred and ninety patients received at least one other treatment, including 10 already in CR after eradication. Altogether, CR was obtained in 70% of patients and the 5-year overall survival was 79% (95% CI [75-83]). CONCLUSIONS: In comparison to clinical series, in the general population, GMLs are more frequently diagnosed at an advanced stage, their clinical management is heterogeneous, and there is a risk of misdiagnosis and overtreatment. These results highlight the necessity of following currently available guidelines in this field.

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.

Exclusive moderate-dose radiotherapy in gastric marginal zone B-cell MALT lymphoma: Results of a prospective study with a long term follow-up.

BACKGROUND: In gastric MALT lymphomas persisting after Helicobacter pylori (H. pylori) eradication, a treatment by moderate-dose radiotherapy (RT) has been proposed but its efficacy has not been confirmed in large prospective series with long term endoscopic follow-up. METHOD: Patients with localised gastric MALT lymphoma persisting after H. pylori eradication were offered moderate-dose RT (30Gy, 2Gy/fraction) and followed with annual endoscopies. All biopsies before and after RT were reviewed by a committee of pathologists. RESULTS: From 1995 to 2011, out of the 232 patients followed prospectively, 53 received RT for persistence of lymphoma after H. pylori eradication: either macroscopic ulcer (n=31), or microscopic lymphomatous infiltrate (n=22), after a mean follow-up of 12 and 31months, respectively. All lymphomas were localised (45 stage IE and 8 stage IIE) and 38 (72%) were H. pylori-positive. The mean clinical and endoscopic follow-up from diagnosis was 7.6years (2.2-19.1). No acute or late toxicity occurred. A complete remission was achieved in all patients but one (98%) with no relapse after a median follow-up of 4.9years (1.3-16.6) after completion of RT. Overall survival and 5-year disease specific survival were 94% and 100%, respectively. One patient died of gastric adenocarcinoma. CONCLUSION: Moderate-dose RT (30Gy) is effective and safe for localised gastric MALT lymphoma persisting after H. pylori eradication.

Small intestinal CD4+ T-cell lymphoma is a heterogenous entity with common pathology features.

BACKGROUND & AIMS: Little is known about intestinal CD4+ T-cell lymphoma; this rare malignancy is misdiagnosed frequently. We evaluated diagnostic criteria and factors that might affect its development and outcome. METHODS: In a retrospective analysis, we analyzed medical records and intestinal specimens from 10 patients diagnosed with intestinal CD4+ T-cell lymphoma among 115 consecutive patients examined for severe enteropathy with villous atrophy. Samples were analyzed by histology, flow cytometry, and comparative genomic hybridization. RESULTS: Small-intestine epithelial and lamina propria tissues from patients who presented with chronic diarrhea and malnutrition had variable levels of infiltration of CD3+ CD4+ T cells. Flow cytometry showed a high frequency of CD4+ intraepithelial cells, which frequently expressed a specific Vß chain. T-cell receptor ß clonality was confirmed by DNA sequencing. Two patients had HLA and serology results compatible with celiac disease and autoimmune enteropathy, respectively. Two patients were found to have antibodies against human T-cell leukemia virus and 2 patients had signs of a recent infection with the herpes viruses. Comparative genomic hybridization analyses showed heterogeneous chromosomal abnormalities. Symptoms were reduced in patients treated with steroids (n = 5), but not in patients given purine analogues or chemotherapy. Antibodies against CD52 produced clinical and histologic responses in 2 of 2 patients, whereas severe adverse effects developed in 1 patient. At the latest follow-up evaluation, all patients were alive. CONCLUSIONS: There is much heterogeneity in the onset and genetic features of intestinal CD4+ T-cell lymphomas, despite their common presentation as indolent lymphoproliferations of the intestinal mucosa. Patients should be treated with steroids, and possibly antibodies against CD52 (for the most aggressive forms of this disorder).

Primary intestinal B-cell lymphoma: a prospective multicentre clinical study of 91 cases.

BACKGROUND & AIMS: Clinical presentation, diagnosis and prognosis of different primary intestinal lymphomas have not been well described and compared so far. Our aim was to prospectively analyse a series of consecutive patients presenting different types of B-cell primary intestinal lymphomas. METHODS: Adult patients with primary intestinal lymphoma, collected between 1991 and 2000 within the multicenter national study in France were evaluated and followed up prospectively. Clinical features and treatment outcomes were analyzed and compared among different groups of lymphomas. RESULTS: Among 91 cases of B-cell primary intestinal lymphomas identified, 38 (41%) were diffuse large B cell lymphomas, 34 (37%) mantle cell lymphomas, 12 (13%) follicular lymphomas, 5 (5%) marginal zone MALT-lymphomas, and 2 (3%) Burkitt's lymphomas. A differential diagnosis could be made on the basis of tumour cell morphology and phenotype assessed by immunohistochemistry. Clinical presentation of the different types of lymphomas varied with respect to age, symptoms, circumstances of diagnosis, and stage. Overall survival was the poorest for mantle cell lymphomas while diffuse large B cell lymphomas could be cured if in complete remission after first line treatment. CONCLUSIONS: This study underlines the existence, within the B-cell primary intestinal lymphomas, of several distinct entities with different clinico-pathological features and prognosis, whose identification is important for choosing appropriate therapeutic strategy.

Risk factors for neoplasia in inflammatory bowel disease patients with pancolitis.

OBJECTIVES: Colorectal cancer (CRC), developing from dysplastic lesions, is the main long-term complication of pancolitis. The aims of the present study were to assess the risks for neoplasia and advanced neoplasia (AN), respectively, in ulcerative colitis (UC) and Crohn's disease (CD) patients with pancolitis, and to search for protective and risk factors for colorectal neoplasia. METHODS: A total of 855 inflammatory bowel disease (IBD) patients with longstanding pancolitis (276 UC, 56 IBD unclassified (IBDu), and 523 CD) had pathological examination of a proctocolectomy specimen (n=255) or multiple biopsy samples from a surveillance colonoscopy (n=600) after median disease duration of 115 months. Risk factors for low-grade dysplasia (LGD) and AN, respectively, were searched for in the whole group of patients and in a case-control comparison after matching for IBD phenotype. RESULTS: A total of 75 patients eventually developed colorectal neoplasia: 14 adenomas, 28 nonadenomatous LGD, and 33 ANs. The 25-year cumulative risks for neoplasia and AN, respectively, were 32.8±5.7% and 25.9±5.7% in UC and IBDu vs. 12.1±2.7% and 3.9±2.0% in CD (P<0.0001). In CD, patients with UC-like endoscopic appearance (n=126) had an increased risk for AN compared with those with discrete lesions (at 25 years, 10.6±7.2 vs. 1.5±0.9%). In the case-control comparison, factors associated with an increased risk of AN were primary sclerosing cholangitis (hazard ratio (HR) 4.72 (1.54-14.52)) and family history of CRC (HR 3.37 (1.02-11.14)), whereas previous segmental colectomy was protective (HR 0.25 (0.07-0.88)). CONCLUSIONS: The risk of AN in longstanding pancolitis is higher in UC or IBDu than in CD. In CD, this risk is significantly increased in patients with UC-like endoscopic lesions. The surveillance program should focus on these latter patients.

Primary gastrointestinal tract mantle cell lymphoma as multiple lymphomatous polyposis.

Primary gastrointestinal involvement of mantle cell lymphoma (MCL) is rare with a frequency reported between 4 and 9% of all gastrointestinal B-cell non-Hodgkin lymphomas. It was first described and so-called as multiple lymphomatous polyposis (MLP). Its clinical presentation is usually characteristic, with multiple lymphomatous polyps involving several digestive tract segments and a marked tendency towards extra-intestinal spread. The constant and typical phenotypic features of the small cleaved tumour cells, characterised as CD20+, CD5+ CD23- with a t(11;14) (q13;q32) and cyclin D1 overexpression on immunochemistry, allow MLP to be considered as the gastrointestinal counterpart of peripheral nodal MCL. They both share a very poor outcome. Response to intensive chemotherapy regimens usually results in regression of macroscopic and sometimes microscopic lesions but remissions are short and median survival from 3 to 4 years. Prognosis has been significantly improved since in younger patients, intensive front-line immunochemotherapy with autologous stem cell transplantation has been proposed. Earlier diagnosis with further studies integrating novel agents are still required to determine the optimal treatment with less toxicity.

FOXP1 abnormalities in lymphoma: translocation breakpoint mapping reveals insights into deregulated transcriptional control.

Deregulation of FOXP1 expression plays an important role in lymphoma development although the underlying molecular mechanism is poorly understood. FOXP1 is targeted by chromosome translocations in MALT lymphoma and diffuse large B-cell lymphoma, where high-level protein expression is associated with poor prognosis. Nonetheless, the incidence and nature of FOXP1 abnormalities at both the genetic and protein levels, and their correlation in these lymphomas are not well established. We investigated FOXP1 translocation, copy number change and protein expression in MALT lymphoma (n=321), MALT lymphoma with a diffuse large B-cell lymphoma component (59), nodal diffuse large B-cell lymphoma (64) and extranodal diffuse large B-cell lymphoma (151) by interphase fluorescence in situ hybridization and immunohistochemistry. FOXP1 translocation was found in eight MALT lymphomas and three MALT lymphomas with diffuse large B-cell lymphoma, with all positive cases originating in the stomach. In diffuse large B-cell lymphoma, the translocation was seen in 5 cases originating in the stomach (2), tonsil (1), large intestine (1) and lymph node (1). Immunoglobulin heavy chain gene was the translocation partner in 11 of the 16 positive cases. Fluorescence in situ hybridization mapping revealed FOXP1 breakpoints within the 5' untranslated region of the gene (upstream of exon 6, the first coding exon of full-length FOXP1) in 14 cases, but downstream of exon 6 (most likely upstream of exon 8) in the remaining 2 cases. Three copies of the FOXP1 gene were observed in MALT lymphoma (17%), MALT lymphoma with diffuse large B-cell lymphoma (12%) and diffuse large B-cell lymphoma (32%), including cases with FOXP1 translocation (19%). Immunohistochemistry showed strong/moderate FOXP1 staining in all the cases with FOXP1 translocation. However, FOXP1 expression was independent of FOXP1 translocation or copy number changes. Our findings suggest that (1) FOXP1 translocation may disrupt the full-length FOXP1 transcript and lead to expression of FOXP1 transcript variants with alternate 5' ends and (2) mechanisms other than translocation and copy number changes are also responsible for FOXP1 overexpression in lymphoma.

Translocations involving the immunoglobulin heavy chain gene locus predict better survival in gastric diffuse large B-cell lymphoma.

PURPOSE: The pathogenesis and clinical heterogeneity of gastric diffuse large B-cell lymphoma (DLBCL) are poorly understood. We have comprehensively investigated the incidence and clinical significance of lymphoma-associated chromosomal translocations, particularly those involving the immunoglobulin heavy chain (IGH) gene locus, in a large series of gastric DLBCL. EXPERIMENTAL DESIGN: One hundred forty-one cases of primary gastric DLBCL [58 with mucosa-associated lymphoid tissue (MALT) lymphoma and 83 without MALT lymphoma] were enrolled. Translocations involving BCL6, c-MYC, FOXP1, MALT1, and IGH were investigated using interphase fluorescence in situ hybridization. In positive cases, additional fluorescence in situ hybridization was done with appropriate probes for potential partner genes. Cases were classified into germinal center B-cell-like (GCB) or non-GCB subgroups by immunophenotyping with CD10, BCL6, and MUM1. RESULTS: Translocations involving IGH were detected in 36 (32%) of 111 cases; their partner genes included BCL6 (n = 10), c-MYC (n = 5), and FOXP1 (n = 3) but remained unknown in the remaining 18 cases. t(14;18)/IGH-BCL2, t(14;18)/IGH-MALT1, and t(1;14)/BCL10-IGH were not detected in any case. t(11;18)/API2-MALT1 was detected in none of the cases, except for one case of DLBCL with MALT lymphoma, which showed positive signals only in MALT lymphoma cells. IGH-involved translocation was associated with younger age but not with any other clinicopathologic factors including GCB or non-GCB immunophenotypes. Cox multivariate analysis revealed that IGH-involved translocation, in addition to younger age and early stage, was an independent prognostic factor for better overall and EFSs. CONCLUSION: IGH-involved translocations are frequent in gastric DLBCL and seem to identify cases with favorable prognosis.

Genetic diversity of the HpyC1I restriction modification system in Helicobacter pylori.

Helicobacter pylori is unique because of the unusually high number and diversity of its restriction modification (R-M) systems. HpyC1I R-M was recently characterized and contains an endonuclease which is an isoschizomer of the endonuclease BccI. This R-M is involved in adherence to gastric epithelial cells, a crucial step in bacterial pathogenesis. This observation illustrates the fact that R-M systems have other putative biological functions in addition to protecting the bacterial genome from external DNA. The genomic diversity of HpyC1I R-M was evaluated more precisely on a large collection of H. pylori strains by PCR, susceptibility to BccI digestion and sequencing. The results obtained support the mechanism of gain and loss of this R-M system in the H. pylori genome, and suggest that it is an ancestral system which gradually disappears during H. pylori evolution, following successive steps: (1) inactivation of the endonuclease gene, followed or accompanied by: (2) inactivation of the methyltransferase genes, and then: (3) definitive loss, leaving only short endonuclease remnant sequences.

Clinical, histological and molecular follow-up of 60 patients with gastric marginal zone lymphoma of mucosa-associated lymphoid tissue.

The persistence of gastric lymphoma after Helicobacter pylori eradication may be difficult to evidence on endoscopic and histological examination. The aims of the study were to evaluate the detection of monoclonal immunoglobulin H (IgH) gene rearrangement in endoscopically infiltrated and normal mucosa at diagnosis and during follow-up in order to determine its clinical and prognostic impact. We studied 60 gastric marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT), and IgH monoclonality was detected at diagnosis in 52 patients (87%). The endoscopically normal mucosa contained clonal lymphomatous cells in 69% of cases before remission. A complete histological remission (HR) was observed in 28 patients (47%). Among them, 23 were followed for molecular remission (MR). The median delay was 10 months to achieve HR and 18 months to achieve MR. Interestingly, patients with HR but not MR had a longer delay to achieve HR (21 months) (P=0.0006) and a more frequent clonal normal mucosa at diagnosis (88%) than patients with both HR and MR (10 months and 39%, respectively). The presence of monoclonal B cells at both infiltrated and normal sites may therefore identify patients with a longer delay to achieve complete response, suggesting that molecular dissemination may require therapeutic intensification.

t(11;18)(q21;q21) of mucosa-associated lymphoid tissue lymphoma results from illegitimate non-homologous end joining following double strand breaks.

t(11;18)(q21;q21) is the most frequent chromosomal aberration specifically associated with mucosa-associated lymphoid tissue (MALT) lymphoma. The translocation fuses the API2 gene to the MALT1 gene and generates a functional API2-MALT1 transcript. The breakpoint of the fusion gene is well characterized at the transcript level but poorly understood at the genomic level and the mechanism underlying the translocation is unknown. We identified the genomic breakpoint in 19 t(11;18)-positive MALT lymphoma cases by polymerase chain reaction and sequencing and analysed the junctional sequences. The breakpoints were scattered in intron 7 and exon 8 of the API2 gene, and introns 4, 6, 7 and 8 of the MALT1 gene. Comparative sequence analysis between the API2-MALT1 fusion on der(11) and the MALT1-API2 fusion on der(18) showed extensive alterations including deletions, duplications and non-template-based insertions at the fusion junctions in all cases examined. An extensive sequence search failed to reveal any known sequence motifs that might be associated with chromosomal recombination or any novel consensus sequences at or near the breakpoints on both der(11) and der(18) except in one case, in which Alu repeats spanned the breakpoint of the MALT1-API2 fusion. Our results suggest that t(11;18) may result from illegitimate non-homologous end joining following double strand breaks.

Evaluation of the association of nine Helicobacter pylori virulence factors with strains involved in low-grade gastric mucosa-associated lymphoid tissue lymphoma.

Helicobacter pylori has been associated with the development of two malignant diseases: gastric adenocarcinoma and gastric mucosa-associated lymphoid tissue (MALT) lymphoma. Although the cag pathogenicity island, especially the cagA gene, has been linked with adenocarcinoma, few data concerning H. pylori pathogenic factors involved in low-grade gastric MALT lymphoma are available. The goal of this study was to analyze the prevalence of and correlation between genes coding for seven H. pylori virulence factors (cagA, cagE, vacA, iceA, babA, hopQ, and oipA) and two novel adhesins (sabA and hopZ) by comparing a collection of 43 H. pylori strains isolated from patients with low-grade gastric MALT lymphoma to 39 strains isolated from age-matched patients with gastritis only. Our results show that taken individually, none of the nine genes tested can be considered associated with MALT strains and allow us to conclude that MALT pathogenesis is not linked with more proinflammatory H. pylori strains. We demonstrated that in patients infected with strains harboring the iceA1 allele, sabA functional status, and hopZ "off" status, the odds of developing a MALT lymphoma were 10 times higher. However, the low prevalence of such strains (10 of 43 MALT strains) renders this triple association a low-sensitivity marker for MALT strains. Our data confirmed that H. pylori virulence factors are correlated with one another. If the involvement of H. pylori in MALT lymphoma is well established, the pathomechanism by which gastric lymphoma occurs remains to be identified.

Which test to use to detect Helicobacter pylori infection in patients with low-grade gastric mucosa-associated lymphoid tissue lymphoma?

Helicobacter pylori is involved in the pathogenesis of lymphoma of the gastric mucosa-associated lymphoid tissue (MALT). Because gastric MALT lymphoma is a rare disease, few studies comparing the accuracy of diagnostic tests in this group of patients have been carried out, and only a limited number of tests (essentially histological) were performed. The aim of our study was to compare the results of four different diagnostic methods used to detect H. pylori (histology, culture, polymerase chain reaction, and serology) in a prospective multicenter study. A patient was considered to be H. pylori positive if culture or histology was positive. During the period 1995-2000, a total of 90 patients with low-grade gastric MALT lymphoma were enrolled. Results for the four tests were available for 56 patients (62.2%). Among these patients, the four tests were concordant in 35 cases (62.5%), i.e., were positive in 19 cases (33.9%) and negative in 16 patients (17.8%). Histology (39/40 positive, 97.5%) and serology (38/40 positive, 95.0%) were the most sensitive tests. Polymerase chain reaction (PCR) and culture were positive in 52.5% and 50%, respectively. The cagA gene was detected in 47.4% of the strains.

High incidence of t(11;18)(q21;q21) in Helicobacter pylori-negative gastric MALT lymphoma.

In approximately 5% to 10% of gastric mucosa-associated lymphoid tissue (MALT) lymphomas, evidence of Helicobacter pylori infection is absent, and their pathogenesis is poorly understood. We reviewed the clinical data and histology, and we examined t(11;18)(q21;q21) and BCL10 expression pattern in 17 such cases. In each case, the absence of H pylori was confirmed by negative serology and histology/immunohistochemistry. Five cases with stage I(E) disease were first treated with antibiotics, and none of them showed any endoscopic or histologic response. Review of the histology failed to identify any apparent difference between gastric MALT lymphomas with and without H pylori infection. Reverse transcription-polymerase chain reaction (RT-PCR) showed t(11;18)(q21;q21) in 9 (53%) of 17 cases, more frequent in lymphomas at stage II(E) or above (5 of 6) than those at stage I(E) (3 of 10). Two t(11;18)(q21;q21)-positive lymphomas were treated by partial gastrectomy and more than 16 years later showed lymphoma relapse in the gastric stump with dissemination to other mucosal sites, poorly responsive to therapy. BCL10 nuclear expression was observed in 7 of 8 t(11;18)(q21;q21)-positive cases and 4 of 7 t(11;18)(q21;q21)-negative cases, including one case suspicious for a BCL10-involved chromosomal translocation. Our results show that t(11;18)(q21;q21) occurs at a high frequency in H pylori-negative gastric MALT lymphomas. Translocation-positive gastric MALT lymphomas tend to be aggressive, and patients with such lymphomas might benefit from prompt treatment and close follow-up.

T(11;18) is a marker for all stage gastric MALT lymphomas that will not respond to H. pylori eradication.

BACKGROUND & AIMS: Eradication of Helicobacter pylori leads to cure of gastric mucosa-associated lymphoid tissue (MALT) lymphoma in 75% of localized cases. However, prolonged follow-up is necessary to determine whether a lymphoma responds to therapy. In a small series of cases, we showed that t(11;18)(q21;q21)-positive MALT lymphomas failed to respond to H. pylori eradication. The present study aimed to verify this finding in a large cohort and confirm whether the translocation predicts the response of stage I(E) tumors, for which clinical staging has little prognostic value. METHODS: A total of 111 patients with H. pylori-positive gastric MALT lymphoma treated with antibiotics were studied. Clinical staging was undertaken before therapy. The response of lymphoma to H. pylori eradication was determined by histologic examination of gastric biopsy specimens. Diagnostic biopsy specimens were analyzed for t(11;18)(q21;q21) by reverse-transcription polymerase chain reaction of the API2-MALT1 transcript. RESULTS: Forty-seven of the 48 patients who showed complete regression had lymphoma at stage I(E), whereas 43 of the 63 nonresponsive cases were at stage I(E) and the remaining cases at stage II(E) or above. t(11;18)(q21;q21) was detected in 2 of 48 complete-regression cases, and these positive cases showed relapse of lymphoma in the absence of H. pylori reinfection. In contrast, the translocation was present in 42 of the 63 nonresponsive cases, including 26 of 43 (60%) at stage I(E). CONCLUSIONS: t(11;18)(q21;q21)-positive gastric MALT lymphomas, including those at stage I(E), do not respond to H. pylori eradication. Detection of the translocation should help the clinical management of patients with gastric MALT lymphoma.