T(11;18) is a marker for all stage gastric MALT lymphomas that will not respond to H-pylori eradication

Background & Aims: Eradication of Helicobacter pylori leads to cure of gastric mucosa-associated lymphoid tissue (MALT) lymphoma in 75% of localized cases. However, prolonged follow-up is necessary to determine whether a lymphoma responds to therapy. In a small series of cases, we showed that t(11;18)(q2:1;q21)-positive MALT lymphomas failed to respond to H. pylori eradication. The present study aimed to verify this finding In a large cohort and confirm whether the translocation predicts the response of stage I-E tumors, for which clinical staging has little prognostic value. Methods: A total of 111 patients with H. pylori-positive gastric MALT lymphoma treated with antibiotics were studied. Clinical staging was undertaken before therapy. The response of lymphoma to H. pylori eradication was determined by histologic examination of gastric biopsy specimens. Diagnostic biopsy specimens were analyzed for t(11.; 18)(q21;q21) by reverse-transcription polymerase chain reaction of the AP12-MALT1. transcript. Results: Forty-seven of the 48 patients who showed complete regression had lymphoma at stage IE, whereas 43 of the 63 nonresponsive cases were at stage IE and the remaining cases at stage IIE or above. t(11;18)(q21;q21) was detected in 2 of 48 complete-regression cases, and these positive cases showed relapse of lymphoma in the absence of H. pylori reinfection. In contrast, the translocation was present in 42 of the 63 nonresponsive cases, including 26 of 43 (60%) at stage I-E. Conclusions: t(11; 18)(q21;q21)-positive gastric MALT lymphomas, including those at stage IE, do not respond to H. pylori eradication. Detection of the translocation should help the clinical management of patients with gastric MALT lymphoma.