Chemotherapy in Treating Children With Recurrent or Refractory Sarcomas

DISEASE CHARACTERISTICS:

* Histologically confirmed malignancy that is relapsed or refractory to conventional therapy at original diagnosis including:

  * Brain tumors

    * Gliomas or astrocytomas
    * Medulloblastomas or primitive neuroectodermal tumor (PNET) in CNS
    * (Brain tumor stratum closed to accrual effective 07/02/2001)
  * Sarcomas

    * Soft tissue sarcoma (undifferentiated sarcoma, embryonal or alveolar rhabdomyosarcoma (RMS), or non-RMS soft tissue sarcoma)
    * Osteosarcoma
    * Ewing's sarcoma/peripheral PNET tumors
  * Neuroblastoma

    * (Neuroblastoma stratum closed to accrual effective 07/02/2001)
* Histology requirement waived for brain stem tumors (Brain tumor stratum closed to accrual effective 07/02/2001)
* Measurable disease documented by clinical, radiographic, or histologic criteria
* Lesions in previously irradiated fields may be used to assess tumor response if there has been evidence of subsequent tumor growth in those fields
* No bone marrow metastases with granulocytopenia and/or thrombocytopenia

PATIENT CHARACTERISTICS:

Age:

* 30 days to 21 years at diagnosis

Performance status:

* ECOG 0-2

Life expectancy:

* More than 2 months

Hematopoietic:

* Absolute neutrophil count at least 1,000/mm3
* Hemoglobin at least 10.0 g/dL (may receive RBC transfusions)
* Platelet count at least 100,000/mm3 (50,000/mm3 if post bone marrow transplantation) (transfusion independent)

Hepatic:

* Bilirubin no greater than 1.5 times normal
* SGOT or SGPT less than 2.5 times normal

Renal:

* Creatinine no greater than 1.5 times normal OR
* Creatinine clearance or radioisotope glomerular filtration rate at least 70 mL/min

Neurologic:

* No greater than grade 2 CNS toxicity OR
* Stable CNS status for brain tumors (Brain tumor stratum closed to accrual effective 07/02/2001)
* Seizure disorders allowed if well-controlled with anticonvulsants

Other:

* Not pregnant or nursing
* Negative pregnancy test
* Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

* At least 3 months since prior bone marrow transplantation and recovered
* At least 2 weeks since prior cytokines and recovered
* No concurrent filgrastim (G-CSF) or other cytokines
* No concurrent immunomodulating agents

Chemotherapy:

* At least 2 weeks since prior chemotherapy (4 weeks for nitrosoureas) and recovered
* No prior topotecan or other camptothecins
* No other concurrent anticancer chemotherapy

Endocrine therapy:

* Concurrent corticosteroids for CNS tumors with increased intracranial pressure allowed (Brain tumor stratum closed to accrual effective 07/02/2001)

Radiotherapy:

* At least 2 months since prior craniospinal radiotherapy or radiotherapy to more than 50% of the bone marrow and recovered
* Concurrent radiotherapy to localized painful lesions allowed provided that at least 1 measurable lesion is not irradiated

Other:

* Recovered from any other prior therapy