Survival after cord blood transplantation from unrelated donor as a second hematopoietic stem cell transplantation for recurrent pediatric acute myeloid leukemia

The Japan Cord Blood Bank Network (JCBBN) reports the treatment of 22 children with acute myeloid leukemia (AML) who received umbilical cord blood transplantation from unrelated donors (CBT) as their second hematopoietic stem cell transplantation (HSCT). Provided by the JCBBN, between February 1997 and September 2006, 22 patients had CBT as a second HSCT. In the initial HSCT, eight received autologous, seven received CBT, and the remaining had allogenic BMT. At the time of CBT as a second HSCT, seven were in the second complete remission (CR2), two in the third CR (CR3), the remaining were not in remission. Reduced intensity conditioning (RIC) conducted for 10 cases and myeloablative conditioning (MAC) for 12 cases. The overall survival rate was 31.3%, 5 years after CBT. Second complete remission at second transplantation was favorable prognosis (58.3 ± 18.6%, compared with 17.1 ± 10.8% for the non-CR group. Mortality after CBT as a second HSCT accounted for 15 cases, 8 from treatment-related mortality. In conclusion, CBT combined with RIC as second HSCT may be useful against a recurrence of AML in children after the initial HSCT.