Unrelated bone marrow transplantation for high-risk anaplastic large cell lymphoma in pediatric patients: a single center case series.

OBJECTIVES: The use of allogeneic stem cell transplantation in NHL patients is not yet clearly defined, especially in children and adolescents, but this option offers the advantages of a tumor-free graft and the possible induction of a graft-vs.-tumor effect.

PATIENTS AND METHODS: We report the results of four consecutive pediatric patients affected by anaplastic large cell lymphoma (ALCL) and treated with allogeneic stem cell transplantation from an unrelated donor. The conditioning regimen was based on total body irradiation given in association with etoposide in three patients, and with thiotepa and cyclophoshamide in one patient. Graft-vs.-host disease (GVHD) prophylaxis consisted of cyclosporin, a short course of methotrexate and rabbit antithymocyte globulin.

RESULTS: All patients had rapid engraftment within 3-4 wk for neutrophils and platelets, and achieved a stable full donor chimerism that has been maintained to the last follow-up visit. One patient later developed a restrictive pneumonopathy. This patient had been heavily pretreated during the course of the disease having suffered four relapses and had received a cumulative dose of bleomycin of 160 mg/m(2). After a follow-up of 11-42 months, all patients are alive in complete hematological and molecular remission; and three of them without any chronic GVHD.

CONCLUSIONS: The increasing number of volunteer bone marrow donors and the reduced toxicity of unrelated stem cell transplantation, especially in children, make this therapeutic option worth more extensive investigation in the treatment of high-risk failure ALCL, although more data is needed to evaluate the long-term benefits. In this regard, the presence of factors predictive of worst outcome such as an early relapse (within 12 months from diagnosis), a refractory or relapsing ALCL and the persistent detection on blood or bone marrow of nucleophosmin-anaplastic lymphoma kinase protein (NPM-ALK) transcript may help select the patients eligible to allogeneic related or unrelated stem cell transplantation.