Post-remission therapy of adults aged 60 and older with acute myeloid leukemia in first complete remission: role of treatment intensity on the outcome.

Although complete remission (CR) is achieved in 50 to 70% of older fit patients with acute myeloid leukemia (AML), consolidation therapy in this age group remains challenging. In this retrospective study, we aimed to compare outcome in elderly patients treated with different post-remission modalities, including allogenic and autologous hematopoietic stem cell transplantation (HSCT), intensive chemotherapy, and standard-dose chemotherapy (repeated 1 + 5 regimen). We collected data of 441 patients ≥ 60 years in first CR from a single institution. Median age was 67 years. Sixty-one (14%) patients received allo-HSCT, 51 (12%) auto-HSCT, 70 (16%) intensive chemotherapy with intermediate- or high-dose cytarabine (I/HDAC), and 190 (43%) 1 + 5 regimen. Median follow-up was 6.5 years. In multivariate analysis, allo-HSCT, cytogenetics, and PS had a significant impact on OS and LFS. In spite of a more favorable-risk profile, the patients who received I/HDAC had no significantly better LFS as compared with patients treated with 1 + 5 (median LFS 8.8 months vs 10.6 months, p = 0.96). In transplanted patients, median LFS was 13.3 months for auto-HSCT and 25.8 months for allo-HSCT. Pre-transplant chemotherapy with I/HDAC had no effect on the outcome. Toxicity was significantly increased for both transplanted and non-transplanted patients treated with I/HDAC, with more units of blood and platelet transfusion and more time spent in hospitalization, but no higher non-relapse mortality. This study shows that post-remission chemotherapy intensification is not associated with significantly better outcome as compared with standard-dose chemotherapy in elderly patients for whom, overall results remain disappointing.