Diagnosis and treatment of childhood non-hodgkin lymphoma.

Major advances have been made in the treatment of childhood non-Hodgkin lymphoma (NHL). The recognition that different NHL subtypes require different treatment strategies was fundamental to developing successful therapy regimens. Currently established therapy groups are lymphoblastic lymphoma (LBL) of precursor B- or T-cell type, mature B-cell neoplasms (B-NHL), and anaplastic large cell lymphoma (ALCL). Accurate diagnostic classification is crucial for allocating patients to appropriate treatment groups. Therapy protocols designed to treat children with acute lymphoblastic leukemia (ALL) have proven highly efficacious for treating children with LBL and are associated with event-free survival (EFS) rates up to 80%. For children with B-NHL, a strategy of rapidly repeated short, dose-intense courses proved more efficacious, with EFS rates up to 90%. In patients with ALCL, comparable results are achieved with either strategy, although this group has the highest relapse rate. The price of these efficacious treatments is considerable toxicity. On the other hand, the chance to survive after relapse is still dismal due to the almost complete lack of established salvage regimen. Thus, refinement of the balance between treatment burden and individual patient risk for failure is a major future task. A variety of new treatment options, some already established for treating adult NHL, await evaluation in childhood NHL.