O1-041 - Front-Line Antibiotic Therapy in Early-Stage H. Pylori-Positive Gastric Diffuse Large B-Cell Lymphomas with or Without Malt Features

Abstract

ABSTRACT Background Our earlier study showed that certain proportion of early-stage H. pylori (HP)-positive gastric diffuse large B-cell lymphoma (DLBCL) with features of mucosa-associated lymphoid tissue (MALT), DLBCL(MALT), could achieve long-term complete pathological remission (pCR) after frontline HP eradication therapy (HPE). In this retrospective, explorative study, we evaluate the efficacy of HPE on early-stage gastric DLBCL without features of MALT, the pure (de novo) DLBCL, in comparison with its efficacy on high-grade transformed gastric MALT lymphoma, the DLBCL(MALT). Methods A total of 50 patients of stage IE/IIE1, HP-positive gastric DLBCL with frontline HPE treatment were included. Of them, 16 patients with pure (de novo) DLBCL were retrospectively identified from medical/pathologic review and 34 patients with DLBCL (MALT) were an expanded cohort of one previously reported multicenter prospective study. pCR was defined as regression of DLBCL to Wotherspoon grade 2 or less in all histologic sections of follow-up endoscopic biopsies. Results HP infection was successfully eradicated in 100% (16/16) of the pure (de novo) DLBCL and 94.1% (32/34) of the DLBCL(MALT) patients. A total of 68.8% (11/16) of pure (de novo) DLBCL and 56.3% (18/32) of DLBCL(MALT) patients achieved pCR after HPE. The median time-to-pCR was 2.1 months (95% CI, 0.6–3.7) for pure (de novo) DLBCL and 5.0 months (95% CI, 2.8–7.5) for DLBCL(MALT) (P = 0.024). At a median follow-up of 7.7 years (95% CI, 4.5–10.9), all patients with pCR after HPE were alive and free of lymphoma, except one patient with pure (de novo) DLBCL died of lung cancer. Conclusions Similar to DLBCL(MALT), a substantial portion of early-stage, HP-positive gastric pure (de novo) DLBCL remains HP-dependent and responds to antibiotic treatment. Prospective studies to validate the findings are warranted.