Long-term outcome of intensive chemotherapy for adults with de novo acute myeloid leukaemia (AML):: the nationwide AML-92 study by the Finnish Leukaemia Group

Objective: To investigate the long-term outcome of idarubicin- and cytarabine-based intensive chemotherapy in adult acute myeloid leukaemia (AML). Patients and methods: A total of 327 consecutive patients with de novo AML (promyelocytic leukaemia excluded) aged 16-65 yr were recruited into the study between September 1992 and December 2001. The latest follow-up data were collected in October 2006. After remission achievement with the first (conventional cytarabine) or second (high-dose cytarabine) chemotherapy cycle, three intensive consolidation courses each containing high- or intermediate-dose cytarabine were given. Results: A total of 268 patients (82%) achieved complete remission (CR). CR rate was 82% and 84% for patients < 60 and >= 60 yr of age, respectively. CR rates in patients with favourable (93%) and intermediate/normal karyotypes (87%) were significantly (P < 0.01) higher than CR rate in patients with adverse karyotype (61%). Median relapse-free survival (RFS) for the patients not transplanted in the first CR (n = 195) was 1.7 yr (95% CI: 0.81-2.60). At 4 yr, a plateau of 70% in RFS was reached for patients with favourable karyotypes. The 5-yr survival was 71%, 47% and 37% for the non-transplanted patients (n = 202) with favourable, intermediate/normal and intermediate/abnormal karyotypes, respectively, while only 8% of the patients having adverse karyotype were alive at 5 yr (P < 0.01). Of the patients with favourable, intermediate/normal or intermediate/abnormal karyotypes, respectively, 58%, 41% and 31% were expected to be alive at 10 yr. Conclusion: Idarubicin- and cytarabine-based intensive chemotherapy regimen is very effective in de novo AML for adult patients up to 65 yr of age. New treatment strategies are needed, however, to improve the outcome of the patients with intermediate and adverse karyotypes.