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e19520 Background: We recently showed that gastric “pure” diffuse large B-cell lymphoma (DLBCL) as well as DLBCL with histologic evidence of mucosa-associated lymphoid tissue (DLBCL[MALT]) remains ...

8571 Background: We previously reported that a direct contact of Helicobacter pylori (HP) with B cells results in CagA translocation into the latter, and the translocated CagA regulates intracellul...

e19512 Background: We have recently demonstrated that nuclear expression of BCL10 or NF-κB helps predict H. pylori-independent status; and inflammatory cytokines such as TNF-α may be related to BCL10 nuclear translocation (Blood 2005;106:1037–41;J Biol Chem 2006;281:167–75). Recent studies have been shown that the chimeric protein of t(11;18)(q21;q21) can lead to constitutive NF-κB activity and thereby mediate cell survival and anti-apoptotic signals. The present study was conducted to investigate the molecular mechanism and the clinical efficacy of thalidomide, an TNF-α or NF-κB inhibitor, in H. pylori-independent MALT lymphoma. Methods: Between October 2003 and June 2007, our study enrolled 11 H. pylori-independent MALT lymphoma patients ( 7 men and 4 women; age range, 43 to 79 years; 7 patients who had failed chemotherapy or rituximab) with nuclear expression of BCL10 or NF-κB in pretreatment lymphoma tissues treated at National Taiwan University Hospital with thalidomide 100mg to 200 mg oral given daily. The presence of t(11;18)(q21;q21) was identified by a multiplex reverse transcriptase polymerase chain reaction of the API2-MALT1 chimeric transcript. Results: Three (27.3%) of 11 patients achieved a complete response (CR), and 3 (27.3) of 11 patients achieved a partial response (PR), resulting in an overall response rate of 54.5% (95% CI, 19.5%-89.6%). The median time from thalidomide therapy to CR was 3.0 months (range, 2.7–4.9 months). At a median follow-up of 41.6 months (range, 17.7–63.8 months), the 3-year event-free survival and overall survival after thalidomide treatment was 80.8%, and 88.9%, respectively. The API2-MALT1 fusion transcript for t(11;18)(q21;q21) was detected in 1 (16.7%) of 6 patients with CR or PR, and 4 (80.0%) of 5 patients with stable or progressive disease (P = 0.08). Conclusions: Our results indicate that thalidomide can be an adjuvant treatment for H. pylori-independent MALT lymphoma patients. Additional investigation of the molecular mechanisms and biologic significance of the API2-MALT1 fusion transcript responsible for thalidomide resistance in this group of tumors is needed. No significant financial relationships to disclose.

8093 Background: We have recently demonstrated that early-stage gastric diffuse large B-cell lymphomas (DLBCLs) with MALToma, as well as their MALToma counterparts, may respond to H pylori eradication therapy (HPET). The present study was conducted to evaluate the effect of HPET in stage IE gastric DLBCLs without MALToma. Methods: Seven patients (4 men and 3 women; age range, 35 to 83 years) with H pylori infection and stage IE gastric DLBCL without MALToma received HPET as first-line treatment from June 2002 through May 2006. Additional immunohistochemical reaction with anticytokeratin was performed to exclude lymphoepithelial lesions (minimal MALToma components) in DLBCL. All patients received intensive endoscopic follow-up examinations with biopsy to evaluate tumor response. Patients with significant improvement of gross lesions that accompanied regression of tumor cells were followed up without additional treatment. Patients without significant improvement were immediately referred to systemic chemotherapy. Tumors that resolved to Wotherspoon grade 2 or less after successful HPET were considered as complete histologic remission. Results: Successful HPET was achieved in all patients. There were 5 patients with complete histologic remission. The complete remission rate was 71.4% (95% confidence interval, 45.1% to 97.7%). The median duration between HPET and complete histologic remission was 2.6 months (range, 1.1 to 5.7 months). At a median follow-up of 24.2 months (range, 5.7 to 56.8 months), all patients with complete histologic remission after HPET were alive and free of lymphoma. Conclusions: A substantial portion of early-stage gastric DLBCLs without MALToma remain H pylori-dependent and can potentially be cured by HPET. No significant financial relationships to disclose.