The role of high-dose chemotherapy and stem cell rescue in the treatment of malignant brain tumors.

The outcome for the majority of children with malignant brain tumors remains poor, despite surgery, irradiation and conventional chemotherapy. In an attempt to improve this poor outcome, strategies utilizing high-dose (potentially myeloablative) chemotherapy with autologous stem cell rescue have been developed. These studies, initially conducted in patients with recurrent brain tumors, have now been extended to patients with newly diagnosed malignant gliomas and to young children with various malignant brain tumors at diagnosis in an attempt to avoid irradiation to the brain. The results of several of these studies are summarized, demonstrating durable disease-free survival for a proportion of patients with recurrent malignant gliomas and medulloblastoma/primitive neuroectodermal tumors, as well as encouraging preliminary data in the newly-diagnosed patients.