Application of Risk-Adapted Therapy for Acute Myeloid Leukemia to a Population. Effects of Stem Cell Transplantation on Outcome.

We introduced a risk-adapted treatment program for non-APL AML in four Swedish health regions. The aim was to optimise treatment results by the use of risk group stratification, mainly based on cytogenetic findings at diagnosis. All patients received induction therapy with idarubicin-cytarabine 3+7 and consolidation cycles containing high-dose cytarabine. Stem cell transplantation was done in CR1 in selected patients, sparing patients with low/intermediate risk of relapse the risks associated with transplantation. 279 patients, 77% of all AML patients 18–60 years (median 51 yrs), in the population were included in the program. Cytogenetics was performed in 98%. Excluding APL, 19 patients had low-risk. The intermediate-risk group consisted of 165 patients, 96 with a normal karyotype. 95 patients were allocated to the high-risk group. 6% died < 30 days after diagnosis. CR rate was 80%. 111 transplants, 78 allogeneic/URD and 33 autologous, were performed in CR1. 40% of all patients were alive after five years. Median overall survival time was 887 days in low-risk, 611 days in intermediate risk, 345 days in high-risk patients. Relapse-free survival times were also significantly (p<0.001) different between the three risk groups. 43% of responding patients were alive in first remission after four years. 4-year relapse-free survival was significantly better for both intermediate risk (67%) and high-risk (41%) with allogeneic/URD transplantation than with autologous transplant or chemotherapy alone. Relapse was observed more often among patients treated with chemotherapy alone (42%, p=0.03) or with autologous transplants (42%, p=0.09) than among patients receiving allogeneic/URD transplants in CR1, 22%. Our results do not support the use of autologous transplantation in AML in first remission.