The use of effective
combination chemotherapy for all stages and subtypes of
non-Hodgkin"s lymphoma (NHL) in children has resulted in a striking improvement in cure rates. Event-free survival now ranges from 70% to 90%, depending on the stage of disease and the NHL subtype. Risk-adapted
therapy has resulted in a dramatic improvement in outcome for high-risk patients, at the cost of significantly increased short-term toxicity, and a reduction of
therapy and toxicity for the lower-risk patient, while maintaining the excellent cure rate. Successful risk allocation of patients is dependent on the identification and continual validation of prognostic factors. The specific treatment protocol is the single most important factor predicting outcome today. Traditional prognostic factors such as stage and
tumor burden are useful in selecting the intensity and length of
therapy, rather than as a major
indicator of likelihood of survival. In order to further improve cure rates and decrease toxicity, new
biologic prognosticators need to be found and validated. Some promising avenues for study appear to be the presence or absence of adhesion molecules and of aberrant
proteins that are specific to subtypes of
lymphomas, such as soluble CD30 and
anaplastic lymphoma kinase (ALK), the molecular classification of
lymphomas on the basis of gene expression, and the evaluation of
biologic markers for measuring early response to
therapy.