Interferon Alfa With or Without Isotretinoin in Treating Patients With Metastatic Kidney Cancer

DISEASE CHARACTERISTICS: Histologically confirmed metastatic renal cell adenocarcinoma Histologic confirmation of metastases desirable Progression of metastases within 2 months of study No clinically manifest CNS metastasis Bidimensionally measurable metastases, as follows: Lung lesion with diameter greater than 2 cm Superficial lymph node or skin or subcutaneous lesion with diameter greater than 2.5 cm Lymph node in the mediastinum or retroperitoneal region, liver lesion, or soft tissue lesion visible on CT or ultrasound with initial diameter greater than 2.5 cm No bone lesion without surrounding, measurable soft tissue lesion PATIENT CHARACTERISTICS: Age: 18 to 75 Performance status: WHO 0 or 1 Life expectancy: At least 90 days Hematopoietic: WBC greater than 3,000/mm3 OR Absolute granulocyte count greater than 1,500/mm3 OR Platelet count greater than 100,000/mm3 Hepatic: Bilirubin no greater than 1.1 mg/dL Lipids no greater than 1.5 times normal Renal: Creatinine no greater than 1.6 mg/dL Cardiovascular: No congestive heart failure No significant arrhythmia No complete bundle branch block Pulmonary: No serious concurrent pulmonary illness Other: No recent uncontrolled bleeding No serous effusion No history of autoimmune disease No controlled or uncontrolled active infection No seizure disorder or compromised CNS function No secondary gastrointestinal dysfunction that could interfere with drug absorption No psychological condition that would preclude participation or consent No second malignancy except basal cell skin cancer or carcinoma in situ of the cervix Not pregnant or nursing Fertile patients must use effective contraception PRIOR CONCURRENT THERAPY: Biologic therapy: No prior immunotherapy Chemotherapy: No prior chemotherapy Endocrine therapy: No concurrent hormonal therapy Radiotherapy: At least 3 months since irradiation of target lesions Subsequent progression or new lesion required No concurrent radiotherapy Surgery: Prior nephrectomy required No concurrent surgery Other: No concurrent tetracyclines or hepatotoxic drugs