Irinotecan in Treating Children With Refractory or Progressive Solid Tumors

DISEASE CHARACTERISTICS:

* Histologically or cytologically confirmed solid tumor refractory to standard therapy or for which no known effective therapy exists

  * Brain tumors eligible

    * Histologic verification waived for brain stem gliomas
* Evaluable disease
* No bone marrow involvement

PATIENT CHARACTERISTICS:

Age:

* 1 to 21

Performance status:

* Karnofsky 50-100% (over age 10)
* Lansky 50-100% (age 10 and under)

Life expectancy:

* At least 8 weeks

Hematopoietic:

* Absolute neutrophil count at least 1,500/mm\^3
* Platelet count at least 100,000/mm\^3
* Hemoglobin at least 8 g/dL

Hepatic:

* Bilirubin less than 1.5 mg/dL
* SGPT less than 5 times normal

Renal:

* Creatinine normal OR
* Glomerular filtration rate at least 70 mL/min

Other:

* No uncontrolled infection
* Not pregnant or nursing
* Negative pregnancy test
* Fertile patients must use effective contraception during and for 6 months after study

PRIOR CONCURRENT THERAPY:

Biologic therapy:

* At least 6 months since prior autologous bone marrow transplantation (BMT) (not including stem cell rescue after high-dose chemotherapy)
* At least 1 week since prior growth factors
* No prior BMT with total body irradiation (stratum I)
* No prior BMT with or without total body irradiation (stratum 2)
* No prior allogeneic BMT (all strata)
* No concurrent sargramostim (GM-CSF)
* No other concurrent prophylactic growth factor support during the first course of therapy

Chemotherapy:

* At least 3 weeks since prior myelosuppressive chemotherapy (6 weeks for nitrosoureas)
* No prior irinotecan
* No more than 2 prior multi-agent chemotherapy regimens (stratum 2)
* No other concurrent chemotherapy

Endocrine therapy:

* Concurrent dexamethasone allowed if on stable or decreasing dose for at least 2 weeks prior to study

Radiotherapy:

* At least 6 months since prior craniospinal radiotherapy or radiotherapy to 50% or more of the pelvis
* At least 6 weeks since other prior substantial bone marrow radiotherapy
* No prior central axis radiotherapy, pelvic radiotherapy, and/or total abdominal radiotherapy (stratum 2)

Surgery:

* Not specified

Other:

* Recovered from all prior therapy
* No other concurrent investigational agents
* Concurrent enzyme-inducing anticonvulsants (e.g., phenytoin, phenobarbital, carbamazepine) allowed if on stable dose for at least 2 weeks prior to study (stratum 3)
* Concurrent valproic acid allowed if combined with another enzyme inducing anticonvulsant drug (stratum 3)