Inclusion Criteria:

- Patients more than 19 years old with pathologically proven GIST which is bulky or
marginally resectable

- Patients must have at least one bidimensionally measurable disease site of 5 cm or
greater not previously irradiated. Bone lesions do not qualify.

- Patients must have an ECOG performance of greater than or equal to 2, with projected
survival of at least three months.

- Patients must have adequate laboratory parameters:

Hematologic: Hb >9.0; WBC >3200 and platelets >100,000/mm3; Hepatic: Bilirubin <2.0 and
AST within 4 times upper limit of normal; Renal: Creatinine of less than or equal to 1.6
or eGFR greater than or equal to 50 mL/min

- Men and women who are of childbearing potential must practice strict birth control
for the duration of the study.

- Women of childbearing potential must be non-lactating and non-pregnant with a
negative pregnancy test within two weeks of trial registration.

- The patient, a witness, and attending physician will have signed an IRB-approved
informed consent prior to Sunitinib administration.

Exclusion Criteria:

- Known brain metastases or significant pleural effusion or ascites.

- Uncontrolled hypertension, diabetes, or other medical condition.

- Major surgery within 21 days of registration.

- Patients wtih organ grafts with the exception of prior high dose chemotherapy with
autologous bone marrow (or stem cell) transplantation.

- History of seizures, central nervous system disorders, dementia, or psychosis that
might preclude adequate informed consent or protocol compliance.

- Prior therapy for GIST.

- A history of HIV or hepatitis virus infection.

- Any recent medical condition which, in the opinion of the investigator, makes the
patient unsuitable for study participation.

- Patients with impaired kidney function.