Prognostic value of translocation t(11;18) in tumoral response of low-grade gastric lymphoma of mucosa-associated lymphoid tissue type to oral chemotherapy.

PURPOSE: To determine the impact of translocation t(11;18) on response to oral alkylating agents in gastric mucosa-associated lymphoid tissue lymphoma (GML). PATIENTS AND METHODS: Fifty-three patients with a GML were studied. Helicobacter pylori-positive patients (n = 34) received anti-H pylori treatment and H pylori-negative patients (n = 19) or patients who failed to respond to anti-H pylori treatment received oral alkylating agents. t(11;18) was detected by reverse transcription polymerase chain reaction from frozen gastric biopsies.
RESULTS: t(11;18) was detected in 32% of patients. It was more prevalent in H pylori-negative as compared with H pylori-positive patients (12 of 19 v five of 34 patients; P = .0005). Among 31 H pylori-eradicated patients, t(11;18) was detected in three patients, all of whom experienced treatment failure, and it was absent in 28 patients: 21 patients (75%) were in remission and seven patients (25%) experienced treatment failure (P = .03). Among 21 patients who received an alkylating agent, t(11;18) was detected in 12 patients: five patients (42%) were in remission and seven patients (58%) experienced treatment failure. t(11;18) was absent in nine patients: eight patients (89%) were in remission and one patient (11%) experienced treatment failure by the end of treatment. Four patients in remission relapsed during follow-up (median, 7 years): they all had t(11;18). Durable remission was obtained in eight (89%) of the nine patients without t(11;18) versus one of the 12 patients (8%) with t(11;18) (P = .0003).
CONCLUSION: Presence of t(11;18) in GML is predictive of resistance to oral alkylating agents, with less than 10% of durable remission at long-term follow-up.