The goal of this clinical research study is to find the highest safe dose of gemcitabine that can be given with radiotherapy before surgery to treat sarcoma. This study will also look at how well this treatment controls sarcoma.

Before the start of treatment, participants will have a physical exam, blood tests, a MRI scan, and a chest x-ray. A PET scan may be done if thought necessary.

Participants will receive the drug gemcitabine by vein along with radiation therapy on Days 1, 8, 22, 29, 43, and 50. Radiation treatments will be given 5 days a week for 5 weeks. The gemcitabine and radiotherapy will be given on an outpatient basis. Chemotherapy and/or radiotherapy may be stopped if side effects become severe.

About 4 to 6 weeks after the final dose of gemcitabine, surgery will be done to remove the tumor or to remove any previous surgical scar and leftover tumor.

During the combined treatment, participants will be seen weekly by the doctor in charge of radiotherapy or by the study nurse. Blood tests will be done every week during treatment. A MRI scan and a chest x-ray will be done within 14 days before surgery. A PET scan will be done if thought necessary.

After the surgery is done, participants will return to M. D. Anderson for follow-up visits every 4 months for the first 2 years, every 6 months for 3 years, and then yearly from then on. An ultrasound and MRI scan (of the extremity or trunk) will be done 3 months after completion of all treatment. Ultrasound scans will be performed at each visit. A MRI scan will only be done again at later visits if needed.

This is an investigational study. Gemcitabine is approved for use by the FDA. Its use together with radiation therapy in this study is experimental. About 36 individuals will take part in the study. All will be enrolled at M. D. Anderson.

Inclusion Criteria:

1. Patients with cytologic or histologic proof of Grade II or III resectable soft tissue sarcoma of the extremity or trunk.
2. Patients with both measurable and non-measurable disease. Patients who are S/P pre-referral excision will be eligible.
3. Inclusion of patients with a prior history of malignancy will be at the discretion of the Study Chairman.
4. Patients must have a Zubrod Point Scale of 0 or 1.
5. Absolute neutrophil count must be > 1,500 cells/mm; platelet count greater than or equal to 100,000 platelets/ml; serum creatinine less than or equal to 1.8 mg/dl, serum glutamate oxaloacetate transaminase (SGOT)/serum glutamate pyruvate transaminase (SGPT) less than or equal to 3 x normal, total bilirubin less then or equal to 1.5 mg/dl.
6. Patients must have no uncontrolled coexisting medical conditions.
7. Women of childbearing potential must not be pregnant or breast feeding and must practice adequate contraception.
8. All patients must sign an informed consent.

Exclusion Criteria:

1) Patients with a history of prior radiotherapy in the area of the primary tumor or those in whom the anticipated radiation field would include the perineum, scrotum, or vaginal introitus will not be eligible.