Dose Intensive Chemotherapy for Children Less Than Ten Years of Age Newly-Diagnosed With Malignant Brain Tumors: A Pilot Study of Two Alternative Intensive Induction Chemotherapy Regimens, Followed by Consolidation With Myeloablative Chemotherapy (Thiotepa, Etoposide and Carboplatin) and Autologous Stem Cell Rescue

OBJECTIVES: Investigate the toxicity of and response rate to an intensification of an induction chemotherapy regimen (regimen A: cisplatin, vincristine, cyclophosphamide, and etoposide) by incorporation of high-dose methotrexate with leucovorin calcium rescue in patients with primitive neuroectodermal tumors and evidence of leptomeningeal dissemination (M1, M2, or M3). Investigate the toxicity of and response rate to a new dose intensive induction chemotherapy regimen (regimen C: vincristine, carboplatin, and temozolomide) in children under ten years of age who are newly diagnosed with either high grade gliomas or diffuse intrinsic pontine tumors. (Regimen B closed to accrual effective 3/30/2000; regimen C open to accrual effective 7/21/2000) Investigate the feasibility of utilizing regimen C chemotherapy followed by consolidation with myeloablative chemotherapy and autologous stem cell (either bone marrow and/or peripheral blood) rescue in these patients. (Regimen B closed to accrual effective 3/30/2000; regimen C open to accrual effective 7/21/2000) Investigate the toxicity of and response rate to an intensification of induction regimen A chemotherapy by incorporation of high-dose methotrexate with leucovorin calcium rescue in patients with primitive neuroectodermal tumors and evidence of leptomeningeal dissemination (M1, M2, or M3). Estimate the time to disease progression and the pattern of relapse in patients who do not have radiographic or cytologic evidence of residual disease at the time of consolidation chemotherapy and who, therefore, do not receive post consolidation irradiation. Estimate the time to disease progression and the pattern of relapse in patients who have radiographic or cytologic evidence of residual disease at the time of consolidation chemotherapy and who, therefore, receive post consolidation irradiation. Assess the morbidity and mortality of the consolidation chemotherapy regimen following either regimen C or the intensified regimen A in these patients. (Regimen B closed to accrual effective 3/30/2000; regimen C open to accrual effective 7/21/2000) Assess the impact that irradiation avoidance or the administration of reduced volume craniospinal and/or focused field local irradiation has on neuropsychometric, endocrinological functions, and physical growth. OUTLINE: This is a two regimen study based on disease characteristics. Patients in regimens A, B, and C undergo leukapheresis after receiving filgrastim (G-CSF) by subcutaneous (SC) injections. Regimen A: Patients without evidence of neuraxis dissemination receive five 21 day courses of the following chemotherapy: cisplatin IV over 6 hours on day 0; etoposide and cyclophosphamide IV over 1 hour on days 1 and 2; vincristine IV on days 0, 7, and 14 of courses 1, 2, and 3; and G-CSF SC beginning on day 3 of each course and continuing until blood counts recover or up to 48 hours before the start of the next course. Patients with evidence of neuraxis dissemination also receive high-dose methotrexate IV over 4 hours on day 3 and leucovorin calcium orally or by IV bolus starting 24 hours prior to methotrexate and continuing every 6 hours until methotrexate levels have diminished. Regimen B (closed to accrual effective 3/30/2000): Patients receive three 21-28 day courses of the following chemotherapy: vincristine IV on days 0, 7, and 14 of each course; carboplatin IV over 4 hours on days 3 and 4 of each course; oral procarbazine daily on days 0-4; oral lomustine on days 3 and 4; and G-CSF SC daily beginning 24 hours following the last dose of carboplatin and continuing until blood counts recover or up to 48 hours before the start of the next course. On day 7 of each course, patients also receive peripheral blood stem cell (PBSC) reinfusion following chemotherapy. Oral lomustine is administered only for the first two courses. Regimen C (open to accrual effective 07/21/2000): Patients receive four 28 day courses of the following chemotherapy: carboplatin IV over 4 hours on days 0 and 1 of each course; vincristine IV on days 0, 7, and 14 of the first three courses only; oral temozolomide daily on days 0-4; and G-CSF SC daily beginning on day 5 and continuing until blood counts recover. After regimen A, B, or C and in the absence of disease progression, patients undergo consolidation myeloablative chemotherapy by receiving carboplatin IV over 4 hours on days -8, -7, and -6, and then thiotepa IV over 3 hours followed by etoposide IV on days -5, -4, and -3. Patients with malignant gliomas or unbiopsied diffuse intrinsic pontine tumors do not receive etoposide. On day 0, patients are reinfused with autologous PBSC. Following recovery from consolidation chemotherapy, patients with radiographic or cytologic evidence of residual disease undergo radiotherapy. Patients are followed at 3 months, then every 3 months for the first 2 years, then every 6 months for years 2-4, and then annually thereafter. PROJECTED ACCRUAL: Approximately 96 patients (73 for regimen A and 23 for regimen C) will be accrued for this study. (Regimen B closed to accrual effective 3/30/2000.)