Rituximab and chlorambucil versus rituximab alone in gastric mucosa-associated lymphoid tissue lymphoma according to t(11;18) status: a monocentric non-randomized observational study.

Forty-nine patients, t(11;18)-positive (n = 31) and t(11;18)-negative (n = 18), were treated without randomization with rituximab-chlorambucil or rituximab alone. Evaluation was performed at week (W) 6, week (W) 25 and every 6 months (Wx). Comparing the rituximab-chlorambucil group to the rituximab-alone group, remission was obtained in 93% vs. 66% at W6 (p = 0.01), in 93% vs. 81% at W25 (p = 0.14) and in 93% vs. 76% at Wx (p = 0.07). Comparing the rituximab-chlorambucil group to the rituximab-alone group in t(11;18)-positive patients, remission was obtained in 100% vs. 45% at W6 (p = 0.0005), in 100% vs. 66% at W25 (p = 0.01) and in 96% vs. 55% at Wx (p = 0.01). Comparing the rituximab-chlorambucil group to the rituximab-alone group in t(11;18)-negative patients, remission was obtained in 66% vs. 83% at W6 (p = 0.32), in 66% vs. 92% at W25 (p = 0.22) and in 83% vs. 92% at Wx (p = 0.47). In conclusion, rituximab-chlorambucil is significantly more rapidly efficient than rituximab alone. In t(11;18)-positive patients, the combination is more efficient than rituximab alone. In t(11;18)-negative patients, rituximab alone is as efficient as rituximab-chlorambucil and may be an alternative treatment.