Imatinib in Patients With Desmoid Tumor and Chondrosarcoma

Inclusion Criteria:

* Histological diagnosis of DT or CDS.
* Biomolecular or immunohistochemical evidence of Imatinib mesylate target (KIT, PDGFRα PDGFRβ activation and/or presence of PDGFα or PDGFβ)
* Measurable or evaluable disease
* Surgical resection of local disease unfeasible radically (or unaccepted by the patient, or amenable to become less demolitive, or easier, or likely more feasible, after cytoreduction) and/or metastatic disease.
* ECOG Performance status 0, 1, 2 or 3
* Adequate bone marrow, liver and renal function
* Female patients of child-bearing potential must have negative pregnancy test.
* Male and female patients of reproductive potential must agree to employ an effective method of birth control throughout the study.
* Written, voluntary, informed consent.

Exclusion Criteria:

* Previous treatment with any other investigational or not investigational agents within 28 days of first day of study drug dosing
* Other primary malignancy with \<5 years clinically assessed disease-free interval, except basal cell skin cancer or cervical carcinoma in situ.
* Grade III/IV cardiac problems as defined by the New York Heart Association Criteria
* Severe and/or uncontrolled medical disease (i.e., uncontrolled diabetes, chronic renal disease, or active uncontrolled infection)
* Known brain metastasis.
* Known chronic liver disease (i.e., chronic active hepatitis, and cirrhosis).
* Known diagnosis of human immunodeficiency virus (HIV) infection.
* Previous radiotherapy to \>/=25% of the bone marrow or within the previous 2 months on target lesion.
* Major surgery within 2 weeks prior to study entry.
* Expected non-compliance to medical regimens (e.g. psychiatric diseases).