DISEASE CHARACTERISTICS: Histologically proven metastatic or unresectable carcinoma of the kidney No CNS metastases

PATIENT CHARACTERISTICS: Age: 18 to 70 Performance status: ECOG 0-2 Life expectancy: Greater than 4 months Hematopoietic: WBC at least 3,500/mm3 Granulocyte count at least 2,500/mm3 Platelet count at least 100,000/mm3 PT no greater than 1.3 times upper limit of normal (ULN) Hematocrit at least 28% Hepatic: Bilirubin less than 2.0 mg/dL SGOT no greater than 1.25 times ULN (unless due to tumor) Renal: Creatinine less than 2.0 mg/dL Calcium less than 12 mg/dL Proteinuria no greater than 2.0 by dipstick Cardiovascular: No active angina No uncontrolled congestive heart failure No uncontrolled arrhythmias No myocardial infarction within 6 months Pulmonary: No significant pulmonary disease (RA pO2 less than 60 or pCO2 greater than 50) Other: Not pregnant or nursing Fertile patients must use effective contraception HIV negative No active infection No daily emesis or inability to tolerate solid foods No prior or concurrent second malignancy within 2 years, except: Nonmelanoma skin cancer Carcinoma in situ of the cervix No sever diarrhea (greater than 4 watery stools per day) No active pelvic inflammatory disease No inflammatory bowel disease No uncontrolled seizure disorders No personal or family history of malignant hyperthermia No recent thromboembolism or any condition requiring concurrent anticoagulation

PRIOR CONCURRENT THERAPY: Biologic therapy: No other concurrent biologic therapy Chemotherapy: No prior gemcitabine No prior fluorouracil other than adjuvant fluorouracil received at least 1 year prior to study No other concurrent chemotherapy Endocrine therapy: Concurrent corticosteroids not allowed (except for nausea or vomiting) Radiotherapy: At least 14 days since prior radiation to axial skeleton No concurrent radiotherapy (except to local lesions) Surgery: At least 14 days since prior exploration and biopsy At least 21 days since prior resection with anastomosis No major organ allograft Other: No concurrent barbiturates No concurrent oral anticoagulants No other concurrent investigational drugs or devices