Twenty-years of hematopoietic stem cell transplantation in childhood acute myeloid leukemia: a single-center study from South India

The aim of the study was to analyze the profile and outcomes of children with acute myeloid leukemia (AML) who underwent hematopoietic stem cell transplantation (HSCT) in the last 20 years at our center. A retrospective cross-sectional analysis was performed on children between 0 and 17.99 years of age with AML who underwent HSCT from January 2002 and December 2021 at Apollo Hospital in Chennai, South India, with a minimum follow up of 3 years. Fifty-five children underwent HSCT with a diagnosis of AML and high risk cytogenetics, or for those with favorable cytogenetics: MRD positivity post induction in 29/55 (52.7 %), relapsed AML in 15/55 (27.3 %) and refractory AML in 11/55 (20 %). Twenty-one of the 55 children underwent haploidentical HSCT (38 %), 16/55 (29 %) matched sibling donor (MSD) HSCT and 18/55 (32 %) matched unrelated donor (MUD) HSCT, with engraftment in 51/55 (92.7 %) children. Overall survival was 37/55 (67.1 %) at the end of 3 years, 15/21 (71 %) patients with haploidentical HSCT, 13/18 (72 %) with MUD HSCT, and 9/16 (56 %) with MSD HSCT (p value = 0.002). Relapse was documented in 4/21 (19 %) patients with haplo-HSCT, 3/18 (16 %) with MUD HSCT and 3/16 (18 %) with MSD HSCT, with an overall relapse rate of 10/55 (18 %). Relapse rates were 2/23 (8 %) among those with chronic GVHD versus 8/32 (25 %) among those without (p value = 0.01). The outcomes in our cohort were promising in high risk, relapsed and refractory AML post-HSCT with an overall survival of 67.1 %. Alternate donor transplants are equally efficacious and have reliable outcomes in terms of survival. Chronic GVHD did offer protection against relapse. Potential limitations of the study were the relatively short follow up, and selection bias in patients selected for HSCT.