PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: Not specified Hematopoietic: WBC greater than 3,500/mm3 Platelet count greater than 100,000/mm3 Hepatic: Bilirubin less than 2.0 mg/dL AST less than 2 times normal Alkaline phosphatase less than 2 times normal Renal: Creatinine less than 2.0 mg/dL Cardiovascular: No symptomatic arteriosclerotic coronary artery disease No history of coronary artery disease Other: Fasting triglyceride level less than 210 mg/dL Fasting cholesterol level less than 350 mg/dL No nonmalignant disease that would preclude administration of retinoids No psychiatric conditions that would preclude study compliance Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception during and for 6 months after study