Published on June 09, 2026
Meet the Author: Hemalatha Rangarajan, MD — ‘Impact of Extramedullary Disease at Diagnosis on Outcomes Post Allogeneic Hematopoietic Cell Transplant in Children and Young Adults With AML'
by Hemalatha Rangarajan, MD
Hemalatha Rangarajan, MD, is the first author of the article “Impact of Extramedullary Disease at Diagnosis on Outcomes Post Allogeneic Hematopoietic Cell Transplant in Children and Young Adults With Acute Myeloid Leukemia: A CIBMTR Report.” She shares in this Q&A background on how this research came about, findings that particularly surprised her, and how these findings are guiding current and future initiatives. Read on for this perspective, and then visit Transplantation and Cellular Therapy, the official journal of ASTCT, for the full article.
Nucleus: Can you provide a short overview of what prompted your team to investigate the impacts of extramedullary disease on the outcomes post allogeneic hematopoietic cell transplant (HCT) in children and young adults with acute myeloid leukemia (AML)?
Hemalatha Rangarajan, MD, (HR): Extramedullary disease (EMD) occurs in approximately 10%–25% of children with AML and often necessitates additional site-directed therapy for adequate disease control. Prior studies evaluating the impact of EMD at diagnosis on transplant outcomes have yielded conflicting results, and some centers preferentially incorporate total body irradiation into conditioning regimens for these patients as they may be considered as a higher risk group.
This study was undertaken to assess the impact of EMD at diagnosis on transplant outcomes in a large cohort of pediatric and young adult patients with AML.
Nucleus: Does the presence of extramedullary disease at AML diagnosis truly worsen post‑transplant outcomes in children and young adults, or has its risk been overstated?
HR: The presence of EMD at diagnosis does not appear to independently worsen post‑transplant outcomes in children and young adults with AML, and its risk may have been overstated in prior literature.
In our study, EMD at diagnosis was not associated with inferior survival or increased relapse following allogeneic HCT. Importantly, our cohort excluded patients with active EMD at the time of transplant, and all patients were reported to be in complete remission prior to HCT, suggesting effective clearance of extramedullary disease before transplantation.
These findings indicate that when adequately treated and in remission at the time of transplant, EMD at diagnosis alone should not be considered a high‑risk feature influencing post‑transplant outcomes.
Nucleus: How do relapse risk and survival outcomes after allogeneic HCT compare among pediatric AML patients with central nervous system involvement, other extramedullary disease, or bone marrow–only disease at diagnosis?
HR: In our study, we observed these groups had similar overall survival (OS), non-relapse mortality (NRM), and progression-free survival (PFS).
However, we did find that compared to patients with only bone-marrow disease (Group I), patients with BM and central nervous system (CNS) disease (i.e., Group II [Hazard Ratio (HR), 0.70; 95% Confidence interval (CI), 0.52–0.94; Probability (P) = .020]) and patients with BM + other EMD ± CNS (i.e., Group III [HR, 0.70; 95% CI, 0.46–1.05; P = .086]) had decreased risk of relapse.
Nucleus: Why might children and young adults with extramedullary disease at diagnosis experience lower relapse incidence after HCT despite higher disease risk profiles?
HR: A likely explanation for this observation may be that our cohort included patients who presented with EMD at diagnosis but successfully cleared it and proceeded to HCT in complete remission. This suggests that the ability to clear EMD may serve as a marker of chemo-sensitive disease.
Nucleus: What do large, contemporary CIBMTR data reveal about progression‑free and overall survival in AML patients with extramedullary disease who undergo transplant in complete remission?
HR: Like a prior CIBMTR study focused on adults (reference 8 in the paper), we also observed that EMD at diagnosis did not impact transplant outcomes in children and young adults with AML.
Nucleus: How should these findings influence transplant decision‑making and risk stratification for pediatric and young adult AML patients with extramedullary involvement?
HR: Our findings suggest that the presence of EMD at diagnosis, in isolation, should not be regarded as a definitive indication for allogeneic HCT. Based on our observation, in patients with EMD at diagnosis who were able to clear the disease and proceed to HCT, EMD was not a poor prognostic factor and had minimal impact on post-HCT outcomes in children and young adults with AML.
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Hemalatha Rangarajan, MD
Hemalatha Rangarajan, MD, is a Clinical Associate Professor of Pediatrics in the Division of Blood and Marrow Transplant and Cellular Therapy at Nationwide Children’s Hospital (NCH) in Columbus, Ohio. Her clinical and research interests center on curative therapies for non-malignant disorders including sickle cell disease, adoptive immunotherapy for high-risk blood cancers, and the study of transplant-related complications in children and young adults.
Dr. Rangarajan is also a founding member of REGENT (Real-World Gene Therapy Consortium), a collaborative network advancing research and knowledge sharing on the use of gene therapy for non-malignant disorders. In addition, she serves on committees of the American Society for Transplantation and Cellular Therapy (ASTCT), the Pediatric Transplant and Cellular Therapy Consortium (PTCTC), the Center for International Blood and Marrow Transplant Research (CIBMTR), the Children’s Oncology Group (COG), and the American Society of Pediatric Hematology/Oncology (ASPHO).