Gastric Diffuse Large B-Cell Lymphoma

Abstract: The management of patients with gastric lymphoma has evolved, with a shift toward nonsurgical treatment. The rates of surgical complications in patients receiving chemotherapy have been insufficiently studied. The objective of this study was to assess the frequency of bleeding, perforation, and gastric outlet obstruction in patients who received chemotherapy as primary treatment for gastric diffuse large B cell lymphoma (DLBCL). We reviewed files of all patients with gastric DLBCL who were diagnosed and treated primarily with chemotherapy in our hospital between 1990 and 2005. Eighteen (25%) of 73 patients experienced surgical complications, of whom 6 (8%) underwent surgery. Eight patients (11%), six with active lymphoma, experienced gastric bleeding; one required gastrectomy. Eight patients (11%) developed gastric outlet obstruction, of whom three were treated conservatively, three required surgery, one stopped treatment, and one received further chemotherapy. Six of the eight patients had no evidence of active lymphoma at the time of obstruction. Two additional patients underwent gastrectomy due to resistant or relapsed disease. Gastric perforation was not observed. Median survival was 90 months for the entire series, 94 months for patients with gastric outlet obstruction, and 11.5 months for patients with gastric bleeding. Given the rate of surgical complications, especially gastric bleeding and gastric outlet obstruction, there is still an important role for the surgical consultant in the treatment of patients with gastric DLBCL receiving chemotherapy. Gastric perforation, although frequently cited as a complication, is in fact rarely observed.

Abstract: 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.

Abstract: Diffuse large B cell lymphoma (DLBCL) of the stomach is a heterogenous disease. There are tumors without histological evidence of mucosa-associated lymphoid tissue (MALT) lymphoma, which are classified as pure or de novo DLBCL and those with evidence of MALT, which are classified as DLBCL (MALT). The association between Helicobacter pylori (H. pylori) and gastric MALT lymphoma and remission with H. pylori eradication was shown in the 1990s. In recent years, scientists from Taiwan and others have shown that high-grade gastric lymphomas may be dependent on H. pylori and eradication of this microorganism is effective in these cases. This entity is biologically distinct from H. pylori (-) cases and has a better clinical outcome. There are sufficient data about the complete remission in some of these cases with brief treatment with antibiotics. With this strategy, it is possible to save some of these cases from the harmful effects of standard chemotherapy. It is time to treat these cases with H. pylori eradication. However, strict histopathological follow-up is crucial and histopathological response must be evaluated according to the scoring system proposed by Groupe d’Etude des Lymphomes de l’Adulte. If there is no sufficient response, chemotherapy must be given immediately. These results suggest that H. pylori dependency and high-grade transformation in gastric MALT lymphomas are distinct events.