Autologous stem cell transplantation for high-risk pediatric solid tumors.

Area of Science:

• Pediatric Oncology
• Hematology
• Cancer Therapeutics

Background:

• Solid tumors in children and young adults often respond well to alkylating agents.
• Autologous stem cell transplantation (ASCT) enables higher chemotherapy doses for high-risk cancers.

Purpose of the Study:

• To evaluate the efficacy and outcomes of two autologous stem cell transplantation protocols using alkylating agents in pediatric patients with relapsed or metastatic solid tumors.
• To determine the impact of remission status at the time of transplant on patient survival.

Main Methods:

• A cohort of 24 children and young adults with relapsed/metastatic solid tumors underwent two consecutive ASCT protocols (MT 8911 and MT 9408) primarily using alkylating agents.
• Neutrophil engraftment times were compared between protocols with and without granulocyte-colony stimulating factor (G-CSF).
• Disease-free survival (DFS) and overall survival (OS) were analyzed using the Kaplan-Meier method, with a focus on pre-transplant remission status.

Main Results:

• Disease-free survival was 39% at 2 years and 34% at 4 years post-transplant.
• Patients transplanted in complete remission (CR) had a significantly better 4-year survival rate of 78%, with 6 out of 9 surviving disease-free.
• Conversely, 13 out of 15 patients transplanted in partial remission (PR) died due to disease progression or transplant-related complications. Transplant-related mortality was 12.5%.

Conclusions:

• Autologous stem cell transplantation is a viable consolidation therapy for pediatric patients with high-risk or relapsed solid tumors.
• Achieving complete remission prior to ASCT is critical for improving survival outcomes in this patient population.
• Further research into optimizing ASCT protocols, including the use of growth factors like G-CSF, may enhance engraftment and reduce complications.