Background: We have demonstrated that early-stage high-grade gastric lymphomas, including diffuse large B-cell lymphoma (DLBCL) with histologic evidence of mucosa-associated lymphoid tissue (DLBCL [MALT]) and DLBCL without MALT (“pure” DLBCL), may respond to Helicobater pylori eradication (HPE) therapy. Our recent data revealed that CagA expression is associated with HP-dependence of gastric MALT lymphoma. In this study, we further explore whether CagA expression is associated with the HP-dependence of high-grade gastric lymphoma. Material and Methods: Expression of CagA was evaluated by immunohistochemistry. CagA expression was further confirmed byWestern blot analysis. The association between CagA expression in malignant B-cells and tumor response to HPE was evaluated in 53 stage IE/IIE1 HP-positive high-grade gastric lymphoma patients. Tumors that had resolved to complete histological remission (pCR) score of GELA histological grading system after successful HPE were considered HP-dependent. Results: Between January 2003 and December 2013, a total 35 DLBCL(MALT) and 18 “pure” DLBCL patients who received HPE as frontline treatment were included. We detected CagA expression in 18 (51.4%) of 35 gastric DLBCL(MALT) and in 12 (66.7%) of 18 gastric “pure” DLBCL. CagA expression was higher in HP-dependent tumors than in HP-independent tumors (76.7% (23/30) versus 30.4% (7/23), P= 0.001). Patients with CagA expression responded to HPE quicker than those without (the median time to pCR, 2.3 months [95% CI, 2.08 to 2.52 months] versus 5.1 months [95% CI, 4.41 to 5.79 months], P= 0.021). Conclusions: Our results indicated that CagA can be detected in malignant B-cells of high-grade gastric lymphoma, and the expression of CagA is clinically and biologically associated with HP-dependence.
Date:
2015-09
Relation:
European Journal of Cancer. 2015 Sep;51(Suppl. 3):S662.
