Temozolomide, Vincristine, and Irinotecan in Treating Young Patients With Refractory Solid Tumors

DISEASE CHARACTERISTICS: Histologically confirmed* malignant solid tumor, including brain tumor, at original diagnosis or relapse Refractory disease NOTE: *Histologic confirmation not required for intrinsic brain stem tumors Measurable or evaluable disease No known curative therapy OR therapy proven to prolong survival with an acceptable quality of life exists No known bone marrow metastases PATIENT CHARACTERISTICS: Age 1 to 21 Performance status Lansky 50-100% (for patients ≤ 10 years of age) Karnofsky 50-100% (for patients > 10 years of age) Life expectancy Not specified Hematopoietic Absolute neutrophil count ≥ 1,000/mm^3 Platelet count ≥ 100,000/mm^3 (transfusion independent) Hemoglobin ≥ 8.0 g/dL (RBC transfusions allowed) Hepatic ALT ≤ 110 U/L (upper limit of normal [ULN] for ALT is 45 U/L) Bilirubin ≤ 1.5 times ULN Albumin ≥ 2 g/dL Renal Creatinine clearance or radioisotope glomerular filtration rate ≥ 70 mL/min OR Creatinine based on age as follows: No greater than 0.8 mg/dL (for patients ≤ 5 years of age) No greater than 1.0 mg/dL (for patients 6 to 10 years of age) No greater than 1.2 mg/dL (for patients 11 to 15 years of age) No greater than 1.5 mg/dL (for patients > 15 years of age) Other Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception Neurologic deficits in patients with CNS tumors must be stable for ≥ 1 week prior to study entry No uncontrolled infection No documented allergy to cephalosporins or dacarbazine PRIOR CONCURRENT THERAPY: Biologic therapy Recovered from prior immunotherapy At least 3 months since prior stem cell transplantation or rescue without total-body irradiation No evidence of active graft-versus-host disease At least 7 days since prior antineoplastic biologic agents At least 7 days since prior hematopoietic growth factors No concurrent biologic therapy or immunotherapy No concurrent prophylactic filgrastim (G-CSF) during the first course of study treatment Chemotherapy Recovered from prior chemotherapy Prior temozolomide, vincristine, irinotecan, or topotecan allowed No prior coadministration of temozolomide and irinotecan No disease progression during treatment with either irinotecan or temozolomide More than 3 weeks since prior myelosuppressive chemotherapy (6 weeks for nitrosoureas) No other concurrent chemotherapy Endocrine therapy Patients with CNS tumors must be on a stable or decreasing dose of dexamethasone for ≥ 7 days prior to study entry Radiotherapy Recovered from prior radiotherapy At least 6 months since prior total-body irradiation, craniospinal radiotherapy, or radiotherapy to ≥ 50% of the pelvis At least 6 weeks since other prior substantial bone marrow radiotherapy At least 2 weeks since prior local palliative radiotherapy (small port) No concurrent radiotherapy Surgery Not specified Other No other concurrent investigational drugs No other concurrent anticancer therapy No concurrent enzyme-inducing anticonvulsants, including any of the following: Phenobarbital Phenytoin Carbamazepine Oxcarbazepine No concurrent administration of any of the following: Rifampin Voriconazole Itraconazole Ketoconazole Aprepitant Hypericum perforatum (St. John's wort) No concurrent treatment for clostridium difficile infection