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