Myeloid sarcoma is associated with poor clinical outcome in pediatric patients with acute myeloid leukemia

Area of Science:

• Pediatric Oncology
• Hematology
• Cancer Biology

Background:

• The prognostic significance of myeloid sarcoma (MS) in pediatric acute myeloid leukemia (AML) is debated.
• The role of stem cell transplantation (SCT) in pediatric AML with MS requires further investigation.

Purpose of the Study:

• To investigate the prevalence, clinical characteristics, and prognostic impact of myeloid sarcoma (MS) in pediatric acute myeloid leukemia (AML).
• To evaluate the efficacy of stem cell transplantation (SCT) in pediatric AML patients with MS.

Main Methods:

• Retrospective analysis of clinical data from 884 pediatric AML patients in the TARGET dataset.
• Assessment of MS prevalence, clinical and molecular features, and survival outcomes (EFS, OS).
• Multivariate analysis to determine the independent prognostic value of MS.

Main Results:

• Myeloid sarcoma (MS) was identified in 12.3% of pediatric AML cases.
• MS was associated with younger age (<1 year), abnormal cytogenetics, and KMT2A rearrangement.
• Patients with MS exhibited lower complete remission rates, higher induction mortality, and poorer 5-year event-free survival (EFS) and overall survival (OS). KMT2A rearrangement further worsened outcomes.
• Stem cell transplantation (SCT) did not significantly improve survival in AML patients with MS.
• Multivariate analysis confirmed MS as an unfavorable prognostic factor for EFS (HR 1.670) and OS (HR 1.623).

Conclusions:

• Myeloid sarcoma (MS) at diagnosis is a significant adverse prognostic factor in pediatric acute myeloid leukemia (AML).
• The presence of KMT2A rearrangements in pediatric AML with MS further diminishes clinical outcomes.
• Pediatric AML patients with MS may not derive survival benefits from stem cell transplantation (SCT).