Between February 1991 and April 1994 induction chemotherapy of 32 adult consecutive patients under 65 years with de novo acute myeloid leukemias (AML) was started in the study UHKT-911. They were 19 women and 13 men, aged 18 - 63 (median 44) years. Their AML were classified according to the FAB classification: 3 M0, 3 M1, 9 M2, 14 M4, 3 M5. Induction chemotherapy consisted of 1 - 2 cycles with 3 - 4 doses of daunorubicin (DNR) 45 mg/m2/d i.v. and 14 doses of cytosine arabinoside (Ara-C) 200 mg/m2 per 3-h infusion every 12 hours. After the treatment patients, not being in complete remission, got the HD cycle with 10 high-doses of Ara-C 2000 mg/m2 per 3-h infusion every 12 hours i.v. and DNR 45 mg/m2/d i.v. on days 4 and 5, then the EMi cycle composed of etoposide 100 mg/m2/d i.v. for 5 days and mitozantrone 10 - 12 mg/m2/d i.v. on days 1, 3 and 5. Complete remission (CR) was achieved in 25 of 32 (78 %) patients after 1 - 3 cycles. Five patients died between days 5 and 24 of treatment of infections, two patients were resistant to 4 cycles of induction therapy and survived 8.4 and 13.5 months. Three patients chose allogeneic bone marrow transplantation in their 1st CR from their relatives. Two of them have been living in CR for 115 a 110 months since diagnosis, the third died of sepsis on the day 52 after transplantation. Two patients in CR died of infections after their 2nd. consolidation cycle. Twenty patients in CR completed 2 - 4 consolidation cycles (1 - 3 HD, 1 EMi). Median of their CR duration was 17.8 (2 - 117) months. Relapse appeared in 12 cases after 4.4 - 34.8 (median 12.5) months, 8 patients (6 women and 2 men, aged 29 - 63 years) have remained longer than 5 years in their 1st. CR. Cytogenetic examination of their bone marrow showed a normal karyotype in 4 cases, 1x 46,XX,del(1)(p32p34), 1x 46,XX,16p+, 1x 47,XX,+mar, 1x 46,XX,del(5)(q22q33). After 62 months in CR a pancytopenia with dysplastic bone marrow changes developed in one of them, probably a secondary myelodysplastic syndrome, lasting for further 33 months. Event-free survival at 5 years was 27.5 % (8/29 patients), significantly better (p = 0.046) against 7.5 % (3/40) patients treated without HD cycles in the years 1982 - 1987. The same difference was observed in 7.5-year overall survival (p = 0.036) between the two studies, when 3 of 6 patients 60 - 64 years old remain in their 1. CR.

        Key words: De novo acute myeloid leukemias - Karyotype - Daunorubicin - High doses of cytosine arabinoside - Complete remission - Long-term survival