Out of 515 evaluable patients (median age, 47 years) who entered the study from 1983 to 1986, 67.4% achieved complete remission (CR) after one cycle (256) or two cycles (91) of daunorubicin (DNR) (45 mg/m2 days 1-3), cytosine arabinoside (Ara-C) (200 mg/m2 i.v. days 1-7), and vincristine (VCR) (1 mg/m2 day 2). A partial remission was achieved by 3.7% of patients, 15% were resistant, 11.3% died during hypoplasia, and 2.7% died during induction. Patients achieving CR received one consolidation course in which administration of DNR was limited to 1 day. Two hundred and forty-eight patients were randomized for six courses of maintenance every 6 weeks: either DNR + VRC day 1 + Ara-C s.c. days 1-5, or AMSA 150 mg/m2 day 1 alternating with high-dose (HD)-Ara-C 3 g/m2 q12 h day 1 + 2 or 5-azacytidine 150 mg/m2 days 1-3. Two hundred and thirty-three patients were randomized when bone marrow transplantation (BMT) had not been planned or performed and 15 patients were randomized before the BMT. Sixty patients received BMT, 17 autografts, and 43 allografts. Median time from CR to BMT was 15 weeks. Forty-two patients were not randomized mainly because of toxicity or treatment refusal. Median DFS for both chemotherapy groups was 12 months and 23% were alive at 4 years. Median survival from CR was 22 months, and 34% were alive at 4 years. There was no difference in disease-free interval (DFI) and disease-free survival (DFS) between the two chemotherapy arms. Of 60 transplanted patients, 42% were alive at 4 years.(ABSTRACT TRUNCATED AT 250 WORDS)