OUTLINE: Patients are stratified by performance status (0 vs 1), nephrectomy (yes vs no), site of disease (pulmonary or lymph node metastases only vs other disease site), radiotherapy (yes vs no), and prior adjuvant biologic or hormone therapy (yes vs no). Patients receive intravenous fluorouracil daily for 14 days, and subcutaneous interferon alfa-2b 3 times a week for 6 weeks. Beginning on day 15, patients receive intravenous interleukin-2, 5 days a week and oral isotretinoin 2 times a day for 4 weeks. Treatment courses are 6 weeks, followed by a 2 week rest period. Treatment continues for up to 4 courses in the absence of disease progression or unacceptable toxicity. Patients with partial or complete response may undergo surgical resection. Patients are followed every 2 months for 1 year and then every 6 months thereafter.