PATIENT CHARACTERISTICS: Age: 18 and over Performance status: 0-3 Hematopoietic: Not specified Hepatic: Bilirubin no greater than 1.5 times normal (unless directly attributable to leukemia) Renal: Creatinine no greater than 1.5 times normal (unless directly attributable to leukemia) Cardiovascular: No uncontrolled or severe cardiovascular disease including: Myocardial infarction within 6 months Congestive heart failure Other: No uncontrolled duodenal ulcer No uncontrolled infection No second malignancy within 5 years except curatively treated: In situ cervical cancer Basal cell skin cancer No other serious medical illness that would limit survival to under 2 years No psychiatric illness that would prevent informed consent or compliance No pregnant or nursing women Adequate contraception required of fertile patients