High-dose chemotherapy with autologous hematopoietic stem-cell rescue for patients with malignant brain tumors.

This article reviews recent reports on high-dose chemotherapy combined with autologous stem-cell rescue for patients with newly diagnosed or recurrent malignant brain tumors. Children with newly diagnosed malignant central nervous system (CNS) tumors are included - in these patients it was desirable to avoid radiotherapy. The drugs used were thiotepa, etoposide, cyclophosphamide, busulfan, melphalan, and carboplatin. At a toxic death rate of 8-13%, their toxicity was considered acceptable. However, in patients receiving high-dose chemotherapy, neurologic complications were not uncommon. Therefore, the effects of this drug therapy on the post-treatment cognitive function of long-term survivors must be examined prospectively. Regarding the types of tumor that respond to drug therapy, medulloblastoma and cerebral primitive neuroectodermal tumor (PNET) appear to be good candidates, as are malignant astrocytic tumors in the cerebral hemisphere of children younger than 3 years. On the other hand, brain stem gliomas do not appear to respond well to high-dose chemotherapy. Radiotherapy can be avoided in a significant proportion of young children with malignant brain tumors. Larger patient series need to be studied to determine which patients are most likely to benefit from high-dose chemotherapy and to pinpoint the optimal time for treatment intervention.