A comparison of the outcomes of children with acute myelogenous leukemia in either first or second complete remission (CR1 vs CR2) following allogeneic hematopoietic stem cell transplantation at a single transplant center.

We reviewed 70 consecutive children with AML who received hematopoietic stem cell transplantation (HSCT) in our institution between 1994 and 2005. Forty-seven children were transplanted in CR1 and 23 were transplanted in CR2. BU/CY was the most common pretransplant conditioning regimen for CR1 patients and a TBI-based conditioning regimen was the most common regimen for CR2 patients. Most patients transplanted in CR1 (81%) received related donor HSCT, whereas most of the CR2 patients (74%) received unrelated donor HSCT. Expectedly, there was a significant increase in acute GVHD incidence in CR2 patients (40 vs 25% for grades I-II and 30 vs 10% for grades III-IV; P=0.02) and a significant increase in transplant-related mortality (38 vs 11%; P=0.01). Although the difference between 3-year EFS for CR1 and CR2 was not statistically significant, there was a significantly superior 3-year overall survival for CR1 patients (74 vs 51%; P=0.05). Children with relapsed AML who achieve and maintain remission until HSCT, have a reasonable survival, but the outcome of children receiving HSCT in CR1 remains superior.