Translocation t(11;18)(q21;q21) is not predictive of response to chemotherapy with 2CdA in patients with gastric MALT lymphoma.

BACKGROUND: t(11;18)(q21;q21) resulting in the API2-MALT1 fusion transcript is an exclusive finding in extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma). While it has recently been demonstrated as a negative predictor for gastric MALT lymphoma undergoing eradication of Helicobacter pylori, nothing is known about the relation between t(11;18)(q21;q21) status and response to chemotherapy. We have therefore performed a retrospective analysis of t(11;18)(q21;q21) in patients undergoing chemotherapy with the nucleoside analogue cladribine (2CdA) for gastric MALT lymphoma. PATIENTS AND METHODS: Eighteen cases of gastric MALT lymphoma treated with 2CdA were reviewed, and 17 could be investigated for t(11;18)(q21;q21) by reverse-transcription polymerase chain reaction and fluorescence in situ hybridization. t(11;18)(q21;q21) was correlated with response to chemotherapy.
RESULTS: Of the 17 patients with gastric MALT lymphoma treated with 2CdA, 9 were at stage IE, 2 at stage IIE and 6 at stage IV. Eight cases with stage IE lymphoma were first treated with H. pylori eradication, but none of them showed histological regression during a minimum follow-up of 12 months, and they were subsequently treated with primary chemotherapy. One patient received chemotherapy due to absence of H. pylori infection. Another patient initially rated as stage IE whose gastric lymphoma did not respond developed spread to the lung during follow-up after eradication. All the remaining 13 cases were treated by chemotherapy at the time of diagnosis. Out of these 17, 8 patients (47%) were found to carry t(11;18)(q21;q21). One patient, who was negative for t(11;18)(q21;q21), progressed during chemotherapy and died 5 months after initiation of treatment. One patient each with and without t(11;18)(q21; q21) had a partial response lasting for 14 and >18 months, respectively. One t(11;18)(q21;q21)-positive patient had stable disease for >16 months. The remaining patients achieved a complete remission (CR) following treatment; 6 were positive for t(11;18)(q21;q21), while the remaining 6 were negative. Two patients [1 positive and 1 negative for t(11;18)(q21;q21), respectively] have developed a local relapse following CR and were salvaged by radiotherapy.
CONCLUSION: Our findings suggest that the presence of the API2-MALT1 fusion transcript resulting from t(11;18)(q21;q21) does not adversely affect the response of gastric MALT lymphoma to chemotherapy with 2CdA. 2CdA appears to be an attractive agent for treatment of gastric MALT lymphoma unresponsive to H. pylori eradication, including those positive for t(11;18)(q21;q21). Copyright 2004 S. Karger AG, Basel