Translocation (11; 18) and Gastric High Grade Lymphoma Risk

Abstract

Purpose: Translocation t (11; 18) (q21; q21) is the most frequent chromosomal aberration in extranodal marginal zone lymphoma of the MALT type. This translocation has been associated with an aggressive course but has not been described in high grade gastric MALT lymphoma. Some authors propose that tumors with this translocation rarely or never progress to high grade lymphomas. However, these conclusions are based on examining few specimens. This study examines the frequency of chromosomal translocation t (11; 18) (q21; q21) in lymphomas from patients with low grade and high grade marginal zone lymphoma of the MALT type. Methods: We examined paraffin embedded tissue of patients with gastric marginal lymphoma of MALT type. The presence of the t (11; 18) (q21; q21) was determined using reverse transcription-polymerase chain reaction (RT-PCR); B-actin transcript was amplified to ensure specimen adequacy. Results: We examined 64 paraffin-embedded gastric lymphomas (39 high-grade MALT lymphomas and 22 low-grade MALT lymphomas) from Italy, USA and Japan. The actin transcript was amplified in 61 of 64 cases (95.3%). The t (11; 18) translocation was detected in 21% (8 of 39) cases with high-grade MALT lymphoma vs. 4 of 22 (18%) with low-grade MALT lymphoma [odds 0.861, 95% CI 0.227–3.267]. Conclusions: Translocation t (11; 18) (q21; q21) is characteristic of extra nodal marginal lymphomas of MALT type. It was found in both low-grade and high-grade gastric lymphomas of the MALT type at an approximately same frequency. These results challenges the assumptions that this translocation is absent in high grade lymphoma or that the translocation precludes its progression to high grade lymphoma. Testing for the translocation may provide additional prognostic information or help identify a subgroup where close follow is needed.