Outcome of Haematopoietic Stem Cell Transplantation for children with Acute Myeloid Leukaemia in Hong Kong

Abstract

Purpose: We aimed to review the outcomes of children with acute myeloid leukaemia (AML) who received allogeneic haematopoietic stem cell transplant (HSCT) in Queen Mary Hospital. Methods: We performed a retrospective review of all children with AML who underwent allogeneic HSCT in the past 20 years (1994-2013) and analysed their transplant outcomes. Results: We have performed allogeneic HSCT for 45 children (29 boys and 16 girls) with AML. The median age at HSCT was 9.1 years (range, 0.8 to 18.5 years). Sixteen children were transplanted in first complete remission (CR1), 20 in second remission (CR2), 1 in third remission (CR3), and 8 with non-remission (NR). Donors were matched sibling (MS) (n=19), 1-antigen mismatched parent (MP) (n=2), matched unrelated donor (MUD) (n=11), or 4-6/6 HLA-matched unrelated cord blood (UCB) (single CB: n=10, double CB: n=3). Five-year overall survival (OS) and relapse-free survival (RFS) were 42.7% and 33.6% respectively. Survivals differed significantly with remission status (OS: 55% in CR1, 44.6% in CR2, vs. 14.3% in CR3/ NR; RFS: 55% in CR1, 24.2% in CR2, vs. 14.3% in CR3/ NR). OS but not RFS was significantly better in patients who received UCB compared to MS, MUD, or MP (OS: 68.7% vs. 34.4% vs. 36.4% vs. 0%). OS and RFS were 100% for patients with double cord blood transplant but the followup was short (median 9 months). Transplant-related mortalities in UCB, MS, MUD, and MP were 7.7%, 17.6%, 72.7% and 50% respectively.

Conclusion: Mortality remains high in children with AML despite stem cell transplantation. Outcomes were better for patients transplanted in first complete remission and those who received unrelated cord blood, especially double cord blood.