PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: Expected 2 year survival less than 10% in previously untreated patients Hematopoietic: WBC at least 3,000/mm3 Platelet count at least 100,000/mm3 Hepatic: Not specified Renal: Creatinine clearance at least 50 mL/min Other: No severe infection or medical illness that would preclude study Must be able to swallow and retain oral medications Not pregnant