Early Gastric Mucosa-associated Lymphoid Tissue Research Articles

Early gastric mucosa-associated lymphoid tissue lymphoma treated by endoscopic submucosal dissection.

A previously healthy 66-year-old woman was referred to our hospital for belching with a positive 13C-labeled urea breath test. A coarse nodular lesion was observed upon upper endoscopy ([Fig. 1 a]). She was treated with standard H. pylori quadruple therapy for 2 weeks.

Clinical features & treatment of early-stage gastric mucosa-associated lymphoid tissue lymphoma.

Background & objectives:Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is a common marginal zone lymphoma. The stomach is the relatively common origin of the MALT lymphoma, now termed as extranodal marginal zone B-cell lymphoma. Gastric MALT lymphoma has good prognosis due to clinical response to treatment and favourable overall survival. In this study, clinical characteristics and treatment of patients of early gastric MALT lymphoma were retrospectively analysed.Methods:Seventy patients with stages I–II MALT-lymphoma treated from April 2003 to August 2015 were included. The most common symptoms were abdominal discomfort, nausea, vomiting and other digestive symptoms. Helicobacter pylori eradication was done in patients with proven H. pylori infection. Patients in whom H. pylori eradication therapy was not effective, alternative treatments options including chemotherapy, radiotherapy and surgery, were given.Results:Fifty two patients with H. pylori infection underwent anti-H. pylori therapy, the total effective rate of anti-H. pylori treatment was 92.3 per cent (48/52). Thirty two patients were given anti-tumour treatment, including chemotherapy, radiotherapy and surgery. The total effective rate was 90.6 per cent (29/32). The five-year overall survival rate and five-year progression-free survival rate were 93.4 and 84.2 per cent, respectively.Interpretation & conclusions:For patients with early gastric MALT lymphoma, anti-H. pylori treatment may be effective. Patients with poor results of anti-H. pylori treatment need to be treated with anti-tumour therapy.

Pathophysiology of Gastric MALT Lymphoma

Early gastric mucosa-associated lymphoid tissue (MALT) lymphoma is considered as an antigen-dependent disease associated with long standing antigenic stimulation by Helicobacter pylori (H. pylori) which induces chronic immune response and lymphoid tissue development at the gastric mucosa normally devoid of lymphoid tissue. With disease progression, antigen-independent clones occur via genetic alterations inducing aberrant activation of nuclear factor κB (NF-κB) pathway which is essential for regulation of normal lymphocyte development and activation. Four major translocations, including t (11;18)/API2-MALT1, t (1;14)/BCL10-IGH, t (14;18)/(IGH-MALT1 and t (3;14)/FOXP1-IGH, occur mutually exclusively and lead to generation of cIAP2-MALT1 fusion protein or overexpression of BCL10, MALT1 and Foxp1. Translocation t (3;14)(q27;q32)/BCL6-IGH and t (1;2)(p22;p12)/BCL10-IGκL also occur in some MALT lymphomas. Mutational inactivation of A20, global NF-κB inhibitor, involve the development of especially translocation-negative MALT lymphoma. Downstream effects of most genetic alteration converge on the same NF-κB mediated oncogenic pathway. This review discusses the current advances in the pathophysiology underlying the development of gastric MALT lymphoma and its progression. (Korean J Med 2012;83:689-698)

Expression of the B-Cell Stimulatory Factors BAFF and APRIL in Gastric MALT Lymphomas.

Abstract 1938Poster Board I-961 Background:Early gastric MALT (mucosa associated lymphoid tissue) lymphoma is still dependent on antigen presentation as indicated by the remission after Helicobacter pylori (H.p.) eradication. Autocrine and paracrine secretion of B-cell stimulatory factors by inflammatory bystander cells may sustain lymphoma growth and survival. The TNF (tumor necrosis factor) familiy members BAFF (B cell- activating factor of the TNF family) and APRIL (A Proliferation Inducing-ligand) have previously been shown to be expressed in B-cell lymphomas. Method:We assessed the expression levels of BAFF and APRIL, as well as their receptors BAFF-R (BAFF receptor) and TACI (Transmembrane Activator and CAML Interactor) in 24 patients with early gastric MALT lymphomas by real-time quantitative PCR of snap-frozen biopsy samples. Distant biopsies with gastric MALT, but without evidence for lymphoma, from the same patients were used for intra-individual comparison. A second independent cohort of 28 patients with H.p.-associated chronic gastritis was used for inter-individual comparison. In selected cases immunohistological staining was performed on paraffin-embedded samples. Results:BAFF was significantly up-regulated in lymphoma tissue when compared with chronic gastritis in the inter-individual group (chronic gastritis 0,03 [standard deviation (SD)=0,21] < lymphoma tissue 0,07 [SD=0,16], Mann Whitney test (MWT) p=0,03). APRIL (chronic gastritis 24,01 [SD=19,94]) > lymphoma tissue 10,41 [SD= 6,93], unpaired t-test p=0,007) as well as TACI (chronic gastritis 16,82 [SD=6060,83] > lymphoma tissue 5,34 [SD=8,47], MWT p=0,01) were down-regulated in lymphoma tissue in comparison to the chronic gastritis tissue. No differences could be shown for the same genes in the intra-individual comparison group. No differences were found for BAFF-R between all groups. Immunohistological studies (n=5) confirmed a strong expression of BAFF and APRIL in all MALT lymphoma cases. Conclusions:The higher expression of BAFF in both, lymphoma and non-neoplastic gastritis, in gastric MALT lymphoma as compared to lymphoid tissue of chronic gastritis cases suggests an involvement of BAFF in the development of gastric MALT lymphoma. In addition, the lower expression of TACI as a negative regulator of B-cell development may further support the importance of B-cell stimulatory factors and their receptors. However, the absence of significant differences within a given patient with gastric MALT lymphoma indicates the necessity of additional events for full transformation. Disclosures:No relevant conflicts of interest to declare.