High survival rate with the LMT-89 regimen in lymphoblastic lymphoma (LL), but not in T-cell acute lymphoblastic leukemia (T-ALL).

The most appropriate treatment for lymphoblastic lymphomas (LL) remains uncertain. We treated 27 patients with newly diagnosed LL according to an LMT-89 protocol, which is a modified version of the LMT-81 protocol previously reported in pediatric patients. The median age was 31 years. Mediastinal enlargement was present in 25/27 patients, with pleural effusion in 12. Four patients had central nervous system involvement and 12 had bone marrow involvement and 24/27 (89%) had advanced Ann Arbor stage III-IV disease. Complete remission (CR) was achieved in 20/27 patients, unconfirmed complete remission in three patients (residual mediastinal lesion on computed tomography scan) and four failed induction therapy (ORR: 85%). Twelve patients (44%) remained in continuous CR with a median follow-up of 95 months. Survival at 3 years (when all the events occurred in our series) was 63%. Bone marrow involvement was associated with a poor outcome. Overall survival was 85+/-20% in patients without bone marrow involvement compared to 37+/-30% in patients with bone marrow involvement. The Ann Arbor stage, age and serum lactate dehydrogenase level did not influence outcomes. This LMT-89 protocol is a safe regimen and is highly effective in advanced LL without bone marrow involvement.