Post-remission treatment for adult patients with acute lymphoblastic leukemia in first remission: is there a role for autologous stem cell transplantation?

Allogeneic stem cell transplantation (alloSCT) or autologous SCT (autoSCT) and intensive consolidation/intensification courses plus maintenance chemotherapy for 1 to 2 years are currently the major options for post-remission treatment of adult patients with acute lymphoblastic leukemia (ALL) in first remission. Comparison of their value with respect to relapse prevention, disease-free survival, and overall survival has been impossible until recently when the results of several randomized trials became available. Herein, we try to dissect data from these randomized trials to evaluate the role of autoSCT in patients with ALL in complete remission. Five prospectively randomized trials were found in which patients with a family donor were eligible for an alloSCT and the remaining patients were randomized between autoSCT and continuation chemotherapy. In addition, in two prospectively randomized trials all patients with a donor were eligible for an alloSCT and the remaining patients were eligible for autoSCT. Using intention to treat, in the majority of ALL studies alloSCT is superior to autoSCT or intensive continuation chemotherapy. It still has to be determined which subgroups of ALL benefit most of allogeneic transplantation, since in some trials the advantage of allogeneic transplantation was confined to the standard-risk ALL patients and in other trials to the high-risk patients. With respect to the role of autoSCT compared to continuation chemotherapy, both treatment modalities show equal, although for high-risk ALL inferior, overall survival chances. In one large trial the disease-free survival in the autoSCT arm was inferior to that in the chemotherapy arm. This finding may eventually have an impact on the overall survival rate. Currently, the main benefit of autoSCT may be its short duration compared with the continuation chemotherapy regimen.