Combination Chemotherapy Followed by Bone Marrow and/or Peripheral Stem Cell Transplantation in Treating Patients With Recurrent Medulloblastoma or CNS Germ Cell Tumors

OBJECTIVES:

• Determine the response and progression-free survival in patients with recurrent medulloblastoma or CNS germ cell tumors treated with intensive melphalan and cyclophosphamide followed by autologous bone marrow and/or peripheral blood stem cell rescue.
• Determine the acute and delayed toxic effects of this regimen in these patients.

OUTLINE: Autologous bone marrow and/or peripheral blood stem cells (PBSC) are harvested. Patients then receive intensive cyclophosphamide IV over 1 hour on days -8 to -5 and melphalan IV over 15 minutes on days -4 to -2. Bone marrow is reinfused on day 0. PBSC are reinfused on day 0 if used alone or on day 1 if used after autologous bone marrow transplantation (ABMT). Sargramostim (GM-CSF) is administered IV over 2 hours daily beginning 4 hours after ABMT and continuing until blood counts recover.

Patients are followed every 6 months through year 4 and then annually thereafter.

PROJECTED ACCRUAL: A total of 30 patients will be accrued for this study within 2.5 years.

DISEASE CHARACTERISTICS:

• Diagnosis of recurrent medulloblastoma or CNS germ cell tumor

• Histologic review of the primary intracranial or spinal cord tumor required

• Biopsy and reduction of tumor bulk prior to study encouraged but not required
• No more than 1 prior primary therapy (radiotherapy or chemoradiotherapy) and/or 1 prior salvage therapy

• Patients with progression on salvage therapy ineligible
• Minimal residual disease (tumor bulk no more than 1.5 cm) or in second clinical complete remission (CR)
• Bone marrow infiltration with or without mass lesions or isolated abnormal CSF cytology as the only manifestation of recurrent disease allowed if a clinical CR is first achieved with conventional therapy

PATIENT CHARACTERISTICS:

Age:

• 2 to 25

Performance status:

• Karnofsky 80-100%

Life expectancy:

• More than 8 weeks

Hematopoietic:

• Absolute neutrophil count greater than 1,000/mm^3
• Platelet count greater than 100,000/mm^3

Hepatic:

• Bilirubin less than 1.5 mg/dL
• SGPT less than 80 IU

Renal:

• Creatinine less than 1.2 mg/dL

Cardiovascular:

• LVEF normal

Other:

• No infection
• Able to tolerate vigorous hydration
• Not pregnant
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• See Disease Characteristics
• Prior cyclophosphamide or ifosfamide allowed

Endocrine therapy:

• No concurrent dexamethasone as an antiemetic
• Other concurrent corticosteroids allowed

Radiotherapy:

• See Disease Characteristics
• Pretransplantation radiotherapy boost allowed

Surgery:

• See Disease Characteristics
• Pretransplantation surgery allowed

Other:

• At least 4 weeks since prior therapy except corticosteroids