Rituximab, alkylating agents or combination therapy for gastric mucosa-associated lymphoid tissue lymphoma: a monocentric non-randomised observational study

Background There is no consensus on the standard treatment of gastric mucosa-associated lymphoid tissue (MALT) lymphoma for Helicobacter pylori-negative patients and for patients with persistent disease despite H. pylori eradication. Aim To evaluate the comparative efficacy and safety of alkylating agents and rituximab alone or in combination. Methods In this monocentric retrospective study, which included 106 patients who had not been previously treated with anti-cancer agents, we evaluated the efficacy and safety of oral alkylating agents monotherapy (n=48), rituximab monotherapy (n=28) and the therapy combining both drugs (n=30). Evaluations were performed at weeks 6 (W6), 25 (W25), and 52 (W52) and after 2years (W104). Results After a median follow-up period of 4.9years (range 0.4-17.2years), complete remission and overall response were significantly higher in patients in the combination therapy group at W104 (92% and 100% respectively) compared with patients treated with alkylating agents alone (66% and 68%) and rituximab alone (64% and 73%). The 5-year progression-free survival probabilities were 68%, 70% and 89% in patients treated with alkylating agents alone, rituximab alone and combination therapy respectively. Haematological adverse events were reported in 32 (30%) patients (mostly grade 1) and were more frequent in the two groups receiving alkylating agents (P=0.05 and P<0.001). No toxicity-related death was reported. Conclusions The use of anti-cancer systemic therapy is safe and efficient in gastric MALT lymphoma. In this retrospective study, the combination of rituximab plus chlorambucil seems more efficient than rituximab or alkylating agents alone. Rituximab has a better safety profile than regimens containing alkylating agents.