PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: Not specified Hematopoietic: WBC at least 3,500/mm3 Platelet count at least 125,000/mm3 Hemoglobin at least 12.0 g/dL Hepatic: Bilirubin less than 1.5 mg/dL SGOT less than 2 times upper limit of normal (ULN) Renal: Creatinine less than 1.7 mg/dL Cardiovascular: No symptomatic coronary artery disease No uncontrolled hypertension No prior coronary artery bypass No acute myocardial infarction in the past year Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective barrier contraception for 1 month prior, during, and for 12 months after study Fasting serum triglyceride less than 2 times ULN Cholesterol less than 350 mg/dL No hypersensitivity to vitamin A or retinoids No active malignancy No concurrent acute or chronic medical or psychiatric condition that would preclude compliance or toxicity assessment No concurrent and severe night blindness