4969 - Treatment outcome for gastric mucosa-associated lymphoid tissue lymphoma with Helicobacter Pylori negative

Background

Unlike that for Helicobacter pylori (H.pylori)-positive gastric mucosa-associated lymphoid tissue (MALT) lymphoma, the management strategy for H.pylori-negative MALT lymphoma remains controversial. Therefore, the aim of the present study was to examine the success of each treatment option for H.pylori-negative gastric MALT lymphomas.

Methods

Between June 2000 and June 2017, a total of 89 H.pylori-negative gastric MALT lymphoma patients were enrolled retrospectively. H.pylori-positive status was defined by positive results for the biopsy urease test and histology. They had all been diagnosed by endoscopy and had a complete staging including CT scan. Tumors that had resolved to complete remission score of the GELA histologic grading system were considered treatment responsive.

Results

Sixty-two patients (69.7%) underwent H.pylori eradication therapy. After H.pylori eradication, complete hematologic resonse (ChR) was achieved in 15 patients (24.2%) and pathological minimum residual disease (pMRD) in 13 (21.0%). The median time from H.pylori eradication to ChR or pMRD was 84 days. Fifteen patients received radiotherapy and all of them achieved ChR. Six patients chose combination chemotherapy with or without rituximab as follows, RCVP in 3, CVP in 1, and CHOP in 2. Two patients took subtotal gastrectomy followed by adjuvant CHOP treatment. All of them achieved ChR after chemotherapy. The clinical course after second-line treatment applied to 33 non-responders and six responders with relapse and the second-line treatments resulted in ChR in 30 patients, pMRD in one, and rRD in two patients. The rate of the ChR induction by each treatment was 100% by radiotherapy, 50% by chemotherapy. Median follow-up period was 45.4 months, lymphoma relapse was observed in nine patients (10.1%). Six patients were treated by either chemotherapy (n = 2) or radiotherapy (n = 3). Disease progression was observed in 3 of 33 non-responders. Only one patient showed transformation into diffuse large B-cell lymphoma. Probabilities of overall survival and event-free survival at 10 years were 98.5%, and 61.4%, respectively.

Conclusions

A substantial proportion of patients with H.pylori-negative gastric MALT lymphoma remain antibiotic-responsive and can be cured using radiotherapy and chemotherapy.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.