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

Pediatr Blood Cancer. 2023 Jun 27:e30530. doi: 10.1002/pbc.30530. Online ahead of print.

Abstract

Background: The role of cytoreduction prior to hematopoietic cell transplant (HCT) for patients with pediatric myelodysplastic syndrome (MDS) and related disorders remains unclear.

Procedure: We 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.

Results: Total 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).

Conclusion: Cytoreduction 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.

Keywords: disease control; hematopoietic cell transplantation; myelodysplastic syndromes; pre-transplant cytoreduction.