Chemotherapy of primary malignant brain tumors in children.

Numerous investigators have reported on a variety of chemotherapeutic agents tested in children suffering from recurrent medulloblastoma, brain stem glioma, and ependymoma, in efforts to improve survival and reduce morbidity. Evaluation of such studies is difficult, because there were rarely more than three or four cases of each tumor type. In medulloblastoma, 5-year survival averages 32%; recurrence follows initial therapy by months to years. The recurrence may be intracranial, spinal, or metastatic, making comparison among cases very difficult. Intrathecal methotrexate (MTX) has been successfully used to treat medulloblastoma, with responses reported in about three-fourths of the cases. Intraventricular MTX is lethal when ventricular obstruction is present. MTX has been less useful in therapy of brain stem glioma and ependymoma. BCNU and CCNU have produced responses in patients with ependymoma, medulloblastoma, and brain stem glioma. Vincristine, alone or in combination, has been useful primarily in medulloblastomas. Less experience is available with several newer methods of chemotherapy, but promising results have been reported with procarbazine, 4'-demethyl-epipodophyllotoxin-beta-D-thenylidine-glucosede (PTG, VM 26), and high dose intravenous methotrexate with citrovorum rescue. It is likely that only a nationwide cooperative effort will achieve significant improvement in the chemotherapy of malignant brain tumors in children.