Neoadjuvant and Adjuvant Imatinib Mesylate in Treating Patients With Primary or Recurrent Malignant Gastrointestinal Stromal Tumor

Inclusion Criteria: Histologically confirmed malignant gastrointestinal stromal tumor Potentially resectable primary disease Potentially resectable recurrent disease Local or intra-abdominal/pelvic metastatic disease Documented c-kit (CD117) expression by immunohistochemical analysis of either initial core specimen or, if recurrent disease, from original tumor block Primary disease must be visceral, intra-abdominal, or pelvic in origin At least 1 unidimensionally measurable lesion At least 5 cm for primary disease At least 2 cm for recurrent disease At least 1 viable core biopsy tumor specimen obtained within 8 weeks before registration Performance status - Zubrod 0-2 WBC at least 3,000/mm^3 Absolute neutrophil count at least 1,500/mm^3 Platelet count at least 100,000/mm^3 Bilirubin no greater than 1.5 times upper limit of normal (ULN) ALT/AST no greater than 2.5 times ULN No uncontrolled chronic liver disease Creatinine no greater than 1.5 times ULN No uncontrolled chronic renal disease No New York Heart Association class III or IV cardiac disease Must be able to lie still in the PET scanner for approximately 1-2 hours No uncontrollable hyperglycemia No medical or psychological condition that would preclude study participation No severe or uncontrolled medical disease No active uncontrolled infection No known or suspected hypersensitivity to any component of the study drug Any prior malignancy is allowed provided patient remains disease free from that malignancy Not pregnant or nursing Negative pregnancy test Fertile patients must use effective barrier contraception during and for 3 months after study participation At least 28 days since prior biologic therapy No concurrent filgrastim (G-CSF) or sargramostim (GM-CSF) At least 28 days since prior chemotherapy At least 28 days since prior radiotherapy See Disease Characteristics At least 28 days since prior investigational drugs At least 28 days since prior imatinib mesylate No concurrent therapeutic doses of warfarin Concurrent low-molecular weight heparin or mini-dose warfarin (1 mg per day) prophylaxis is allowed