Unrelated cord blood transplantation for central nervous system relapse in high-risk childhood acute lymphoblastic leukemia

Few clinical studies have investigated the role of unrelated cord blood transplantation (CBT) for central nervous system (CNS) relapse of childhood acute lymphoblastic leukemia (ALL) patients with high-risk factors. The aim of this report is to identify the potential benefits of unrelated CBT in high-risk childhood ALL with CNS relapse who has been treated on CNS-directed treatment strategies. Eleven childhood ALL patients with CNS relapse who underwent unrelated CBT enrolled in our study between 2001 and 2011, and all of the patients had features associated with poor outcomes, such as high white blood cells at diagnosis, ph + chromosome, or a history of bone marrow relapse. All transplants were performed with myeloablative-conditioning therapy (BU/cyclophosphamide (CY2) or total body irradiation/CY) plus highly CNS-active agents (carmustine or high-dose cytarabine). All patients achieved neutrophil engraftment and platelet engraftment. A total of nine patients (81.8 %) developed pre-engraftment syndrome at a median of 7 days, and three patients developed acute graft-vs-host disease at a median of 21 days. The median follow-up after CBT was 28.5 months. The probability of overall survival at 9 years was 63.6 %, and no patient experienced a CNS relapse. Our experience suggests that unrelated CBT appears to be an effective treatment option for CNS relapse of childhood ALL patients associated with poor outcome features.