RATIONALE: Imatinib mesylate may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth.

PURPOSE: This phase I/II trial is studying the side effects of imatinib mesylate and to see how well it works in treating patients with recurrent or refractory aggressive fibromatosis.

OBJECTIVES:

Primary

• Determine the non-progression rate in patients with recurrent or refractory aggressive fibromatosis after 3 months of treatment with imatinib mesylate.

Secondary

• Determine the non-progression rate in patients after being treated with this drug for 12 months.
• Determine the toxic effects of this drug in these patients.
• Determine the tolerance to this drug in these patients.
• Determine the response rate in patients treated with this drug
• Determine progression free and overall survival of patients treated with this drug.
• Determine the quality of life of patients treated with this drug.
• Correlate clinical, biological, and genomic markers with response and long-term stable disease in patients treated with this drug.

OUTLINE: This is a multicenter study.

Patients receive oral imatinib mesylate once daily for up to 12 months in the absence of disease progression or unacceptable toxicity.

Quality of life is assessed periodically.

PROJECTED ACCRUAL: A total of 39 patients will be accrued for this study.

DISEASE CHARACTERISTICS:

• Histologically confirmed aggressive fibromatosis (desmoid tumor)

• Relapse or disease progression despite surgery, chemotherapy, radiotherapy, or any other treatment

• Tumors must meet the following criteria:

  • Ineligible for complete surgical resection by carcinological exeresis OR surgery would cause severe mutilation
  • Cannot be treated with curative radiotherapy

• Measurable disease by RECIST criteria

• No prior malignancy

PATIENT CHARACTERISTICS:

• Not pregnant or nursing
• Fertile patients must use effective contraception during and for 6 months after completion of study treatment
• Absolute neutrophil count > 1,000/mm^3
• Platelet count > 100,000/mm^3
• Bilirubin < 1.5 times upper limit of normal (ULN)
• SGOT and SGPT < 2.5 times ULN
• Creatinine ≤ 2.5 times normal
• No severe liver failure
• No chronic somatic or psychiatric illness that would preclude study compliance
• No known hypersensitivity to imatinib mesylate or one of its components
• No geographical, social, or psychological reason that would inhibit follow-up

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics

• No concurrent immunomodulators*

• No concurrent hormonal treatments* if used for fibromatosis

• No concurrent cytotoxic drugs*

• No concurrent nonsteroidal anti-inflammatory drug* if used for fibromatosis

  • Allowed if used as an analgesic 3 months prior to disease progression

• No concurrent participation in another therapeutic investigational trial NOTE: *If disease progression has occurred during this treatment, then the treatment must have ended ≥ 1 month prior to study entry

Individual Participant data will not be shared at an individual level.