Imatinib Mesylate in Treating Patients With Locally Advanced or Metastatic Dermatofibrosarcoma Protuberans or Giant Cell Fibroblastoma

DISEASE CHARACTERISTICS:

• Histologically confirmed dermatofibrosarcoma protuberans or giant cell fibroblastoma
• Locally advanced or metastatic disease
• Measurable disease
• Not amenable to surgery, radiotherapy, or combined modality therapy with curative intent
• Documented progressive disease within the past 3 months
• Previously irradiated lesions must show disease progression
• Tumor expressing COL1A1/PDGF-beta by fluorescence in situ hybridization
• Translocation t(17;22)(q22;q13)
• No prior chemotherapy OR previously treated with 1, and only 1, line of combination chemotherapy with ifosfamide and doxorubicin OR 2 lines of single-agent therapy OR relapsed within 6 months after adjuvant chemotherapy

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• WHO 0-2

Life expectancy

• Not specified

Hematopoietic

• Absolute neutrophil count ≥ 2,000/mm^3
• Platelet count ≥ 100,000/mm^3
• Hemoglobin ≥ 9 mg/dL* NOTE: *Transfusion allowed

Hepatic

• SGOT or SGPT ≤ 2.5 times upper limit of normal (ULN) (5 times ULN if hepatic metastases are present)
• Bilirubin ≤ 1.5 times ULN
• No uncontrolled hepatic disease

Renal

• Creatinine ≤ 1.5 times ULN
• No uncontrolled renal disease

Other

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception during and for 3 months after study participation
• HIV negative
• No uncontrolled diabetes
• No active or uncontrolled infection
• No concurrent severe or uncontrolled medical disease
• No medical, psychological, familial, sociological, or geographical condition that would preclude study participation, compliance, or giving informed consent
• No other malignancy within the past 5 years except adequately treated basal cell or squamous cell skin cancer, carcinoma in situ of the cervix, or adequately treated stage I or II cancer currently in complete remission

PRIOR CONCURRENT THERAPY:

Biologic therapy

• More than 28 days since prior biologic therapy
• No concurrent filgrastim (G-CSF) or sargramostim (GM-CSF)
• No concurrent anticancer biologic agents

Chemotherapy

• See Disease Characteristics
• More than 28 days since prior chemotherapy
• No concurrent chemotherapy

Endocrine therapy

• Not specified

Radiotherapy

• See Disease Characteristics
• At least 6 months since prior radiotherapy
• No concurrent radiotherapy
• Concurrent palliative radiotherapy allowed provided radiotherapy will not be administered to a target lesion

Surgery

• Not specified

Other

• More than 28 days since prior investigational drugs
• No concurrent therapeutic anticoagulation therapy with warfarin
• Concurrent low-molecular weight heparin or mini-dose warfarin for prophylaxis of central venous catheter thrombosis allowed
• No other concurrent anticancer agents
• No other concurrent investigational drugs
• No other concurrent cytostatic agents
• No other concurrent tyrosine kinase inhibitors