Persistent monoclonality after histological remission in gastric mucosa-associated lymphoid tissue lymphoma treated with chemotherapy and/or surgery: Influence of t(11;18)(q21;q21)

Abstract

The purpose of this work was to study retrospectively the molecular response and outcome of 19 gastric mucosa associated lymphoid tissue (MALT) lymphoma patients achieving histological remission after chemotherapy or surgery. Immunoglobulin heavy chain variable (IgV_H) gene rearrangements were studied by PCR in biopsies obtained at diagnosis and follow-up. Presence of t(11;18)(q21;q21) was studied by FISH or RT-PCR. Sequencing analysis of three t(11;18)(q21;q21) positive and two negative lymphomas with persistent monoclonal IgV_H rearrangements was also performed. Long-term IgV_H monoclonality was demonstrated in 11/19 patients (58%); in five of them monoclonal rearrangements were present in all samples throughout the follow-up. Persistent IgV_H monoclonality was detected a median of 49 months after the achievement of histological response and did not condition histological relapse in most cases. All three t(11;18)(q21;q21) positive patients had maintained IgV_H monoclonality and sequencing analyses revealed the same mutated IgV_H alleles in the diagnostic and the follow-up samples. Over half of the patients with gastric MALT lymphoma with histological response after chemotherapy and/or surgery have long-term persistent monoclonality. The presence of t(11;18)(q21;q21) seems to condition long-term persistence of the initial lymphoma clone.™

Keywords:

• MALT lymphoma
• gastric lymphoma
• H. pylori
• t(11;18)(q21;q21)

Notes

This study has been presented at the 49th Annual Meeting of the American Society of Hematology 2007.