Gemcitabine Plus Cisplatin in Treating Patients With Metastatic Kidney Cancer

DISEASE CHARACTERISTICS: * Histologically proven metastatic renal cell carcinoma * No brain metastases PATIENT CHARACTERISTICS: Age: * Over 18 Performance status: * ECOG 0-2 Life expectancy: * At least 12 weeks Hematopoietic: * WBC at least 3,500/mm\^3 * Hematocrit at least 30% * Platelet count at least 100,000/mm\^3 Hepatic: * Bilirubin no greater than 2.0 mg/dL * AST and ALT no greater than 1.5 times upper limit of normal Renal: * Creatinine no greater than 1.5 mg/dL OR * Creatinine clearance at least 60 mL/min Cardiovascular: * No uncontrolled hypertension * No myocardial infarction within the past 8 weeks Other: * Not pregnant or nursing * Fertile patients must use effective contraception * No other prior malignancy within the past 5 years except nonmelanomatous skin cancer, carcinoma in situ of cervix, prostate intraepithelial neoplasia, or superficial bladder cancer * No significant psychiatric disease * No active infection PRIOR CONCURRENT THERAPY: Biologic therapy: * No more than 2 prior biologic response modifier regimens * No concurrent biologic therapy Chemotherapy: * No prior chemotherapy * No other concurrent chemotherapy Endocrine therapy: * Not specified Radiotherapy: * Prior radiotherapy allowed if measurable disease is outside radiation port * At least 28 days since prior radiotherapy * No concurrent radiotherapy Surgery: * Prior surgery allowed