A comprehensive multicenter study has revealed both the effectiveness and significant risks associated with tandem autologous stem cell transplantation (ASCT) in treating pediatric high-risk neuroblastoma, highlighting critical complications that can impact patient outcomes.
The retrospective analysis, presented by Dr. Zahra Hudda at the 2025 Tandem Meetings, examined 255 pediatric patients who underwent tandem ASCT between January 2014 and June 2021. While achieving a promising 94% six-month survival rate, the study uncovered serious complications that warrant careful monitoring.
Patient Demographics and Disease Characteristics
The study cohort comprised predominantly male patients (60%) with a median age of 38 months at diagnosis. The majority (90.6%) had neuroblastoma, with most cases (80.8%) originating in the abdomen/pelvis region. Notably, 94.2% of patients presented with metastatic disease, and 74.1% showed bone marrow involvement.
Transplant Outcomes and Complications
Of the 255 patients who began treatment, 242 (95%) completed both ASCT cycles. The first transplant was administered at a median age of 45 months, with patients requiring a median 26-day hospital stay. However, 14 patients (5%) could not proceed to the second transplant due to various complications.
Following the second transplant, significant complications emerged:
- 17.1% developed bloodstream infections
- 19.9% required ICU admission
- 12% experienced respiratory failure requiring intubation
- 17.8% suffered acute kidney injury
- 14.9% developed hypertension requiring multiple medications
Endothelial Disorders: A Major Concern
The study identified endothelial disorders as a significant challenge, with 23% of patients developing complications after the second transplant:
- 16% developed thrombotic microangiopathy (TMA)
- 9% experienced veno-occlusive disease (VOD)
- 4% suffered from diffuse alveolar hemorrhage (DAH)
Risk Factors and Survival Impact
Key risk factors for complications included:
- Increased fever days
- Acute kidney injury
- ICU admission
- Respiratory failure requiring intubation
The six-month overall survival rate of 94% was achieved despite these challenges, though patients who developed endothelial disorders showed poorer outcomes. Among the 14 reported deaths, the primary causes included respiratory failure, multi-organ failure, and VOD, with most deaths occurring at a median of 41 days post-transplant.
Future Directions
Dr. Hudda emphasized the importance of routine screening and early intervention for endothelial disorders. "As novel targeted agents and cellular therapies emerge, reducing endothelial dysfunction should remain a key focus," she noted. Future research will examine long-term outcomes, relapse rates, and correlations between prognostic factors and treatment responses.
