Long-term outcomes for acute myeloid leukemia patients treated with reduced intensity conditioning and hematopoietic stem cell transplant

This study aimed to investigate the long-term outcomes for patients with acute myeloid leukemia who received reduced-intensity conditioning and allogeneic stem cell transplant. 

This study concluded that this treatment is safe and effective in these patients in the long-term.  

One of the standard treatments for acute myeloid leukemia (AML) is allogeneic hematopoietic stem cell transplantation (allo-HSCT). Allo-HSCT is a procedure in which a person receives blood-forming stem cells from a genetically similar, but not identical, donor. This is often a sister or brother but could be an unrelated donor. Before allo-HSCT, a conditioning regimen is given. Conditioning is chemotherapy meant to kill cancer cells before new, healthy cells are received.

Normally, a myeloablative conditioning regimen is given (MAC). However, this is often associated with increased risks of side effects, particularly in older people. Reduced-intensity conditioning (RIC) is a conditioning regime that uses less chemotherapy and radiation that the standard MAC regime. 

However, the long-term outcomes of allo-HSCT with RIC for patients with AML is unknown. 

This study involved patients with AML aged 50 years who underwent allo-HSCT. 284 patients received allo-HSCT and RIC. 190 patients received allo-HSCT and MAC. RIC patients were followed for an average of 10.1 years. MAC patients were followed for an average of 10.4 years.  

There were no significant differences in outcomes between the 2 groups. The 10-year probability of overall survival (OS) was 36.4% for the RIC group compared to 39.8% for the MAC group. The 10-year probability of relapse was 30% for the RIC group compared to 26.3% for the MAC group. The 10-year probability of non-relapse mortality (NRM; mortality not related to relapsed disease) was 35.7% for the RIC group compared to 35.5% for the MAC group.  

This study concluded that RIC allo-HSCT in older patients with AML is safe and effective in the long-term. 

Patients in the RIC group were older and the sources of stem cells were also different between groups. This might have affected the results.