Impact of cytoreduction and remission status on hematopoietic cell transplantation outcomes in pediatric myelodysplastic syndrome and related disorders

Abstract

AbstractBackgroundThe role of cytoreduction prior to hematopoietic cell transplant (HCT) for patients with pediatric myelodysplastic syndrome (MDS) and related disorders remains unclear.ProcedureWe performed a single‐center retrospective analysis of pre‐transplant disease management and subsequent HCT outcome for pediatric patients with MDS and related disorders who underwent HCT between 2010 and 2020.ResultsTotal 62 patients (median age 11 years) with idiopathic MDS (n = 16), MDS secondary to an underlying germline condition (n = 11), secondary acute myeloid leukemia (n = 9), myeloproliferative neoplasms (n = 8), and treatment‐related myeloid neoplasms (n = 18) received an allogeneic HCT. Cytoreduction prior to HCT was performed in 30/62 (48%) patients; this subset of patients had higher risk disease characteristics, including a higher blast count on presentation. In the overall cohort, use of cytoreduction before HCT was associated with higher rates of relapse (cumulative incidence of relapse 24 months post HCT: 48.1% [27.5%–66.1%]) for those who received cytoreduction versus 16.6% (5.9%–32.1%) for those who did not (p = .03). There was a trend toward decreased overall survival (OS) for those patients who received cytoreduction (24 months post HCT 57.1% vs. 75.3%, respectively; p = .06). OS for patients who received cytoreduction and attained measurable residual disease (MRD) negativity prior to HCT was superior compared to those with persistent disease (24 months post HCT 63.9% [36%–81.2%] vs. 33.3% [7.8%–62.3%], respectively; p = .04).ConclusionCytoreduction did not provide survival benefit in our overall cohort, but its increased use in children with higher risk disease impacted the analysis. Patients receiving cytoreduction and achieving MRD‐negative status before HCT demonstrated improved OS compared to those with persistent disease.