Imatinib Mesylate in Treating Patients With Advanced Soft Tissue Sarcoma or Bone Sarcoma

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed metastatic or unresectable locally advanced (stage IV or recurrent) soft tissue or bone sarcoma * Eligible subtypes: * Ewing's family (e.g., primitive neuroectodermal tumor) * Osteosarcoma * Synovial sarcoma * Rhabdomyosarcoma (e.g., alveolar, embryonal, or pleomorphic) * Liposarcoma (all variants) * Malignant fibrous histiocytoma * Peripheral nerve sheath (e.g., malignant peripheral nerve sheath tumor, neurofibrosarcoma, or schwannoma) * Fibrosarcoma * Angiosarcoma (all variants) * Failed standard therapy with no available salvage regimens * Unidimensionally measurable target lesions by x-ray, CT scan, MRI, PET, or physical examination * Must be outside prior irradiation fields or have documented disease progression at least 6 weeks after completion of prior radiotherapy PATIENT CHARACTERISTICS: Age: * 10 and over Performance status: * Not specified Life expectancy: * Not specified Hematopoietic: * Not specified Hepatic: * Bilirubin no greater than 3 times upper limit of normal (ULN) * ALT and AST less than 2.5 times ULN Renal: * Creatinine less than 1.5 times ULN Other: * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective barrier contraception during and for at least 1 week after study participation for female patients and for at least 3 months after study participation for male patients PRIOR CONCURRENT THERAPY: Biologic therapy: * Not specified Chemotherapy: * Not specified Endocrine therapy: * No hormonal birth control Radiotherapy: * See Disease Characteristics * At least 3 weeks since prior radiotherapy and recovered Surgery: * Not specified Other: * At least 28 days since any prior systemic therapy