Feasibility and recent improvement of autologous stem cell transplantation for acute myelocytic leukemia in patients over 60 years of age: Importance of the source of stem cells

We investigated on the outcome of patients with AML 60 year old and older who received an autograft within EBMT. The population consisted of 193 patients from 60 to 74 years of age (median 63) autografted from 1/84 to 12/98. 147 patients were in CR1. The source of stem cells was peripheral blood (PB) in 128, bone marrow in 51, and a combination of both in 14. 97% of patients had successful engraftment, on leukocytes on day 14 (6-57), neutrophils on day 15 (7-71) and platelets on day 30 (9-894). In patients autografted in CR1, the transplant related mortality (TRM) was 15±4%, the relapse incidence (RI) 58±5%; the leukemia free survival (LFS) 36±5% and the overall survival 47±5% at 3 years. The source and dose of stem cells were studied in particular: in patients transplanted in CR1, the RI was 44±11% in those receiving marrow versus 63±6% in those receiving PB (p=0.04). The dose in CFU-GM collected was available in only 59 patients, including 53 in CR1. Patients autografted in CR1 who received the higher doses (above median) had a lower RI (47±11% versus 79±9%, p=0.009). Finally, there was a significant improvement for patients transplanted after March 1996: for those in CR1, the RI was 41±8% versus 65±6% (p=0.01), the LFS 53±8% versus 28±5% (p=0.01) and the overall survival 72±7% versus 36±6% (p=0.02). By multivariate analyses, significant factors for the outcome were the date of transplant with recent improvement and the source of stem cells, with lower RI for marrow. In conclusion, the present survey indicates that ASCT is a potential therapeutic approach in patients with AML over 60 years of age and that results have improved recently.