Risk factors for outcome after allogeneic stem cell transplantation in patients with advanced phase CML

Area of Science:

• Hematology
• Oncology
• Transplantation Medicine

Background:

• Allogeneic hematopoietic stem-cell transplantation (HSCT) is the sole curative treatment for advanced chronic myeloid leukemia (CML).
• Outcomes for advanced CML patients undergoing HSCT have historically been poor with limited follow-up data.

Purpose of the Study:

• To evaluate the long-term outcomes of HSCT in patients with advanced CML (Blast Crisis or Accelerated Phase).
• To identify risk factors influencing overall survival (OS) and progression-free survival (PFS) after HSCT for advanced CML.

Main Methods:

• Retrospective analysis of 147 patients with CML in Blast Crisis (BC) or Accelerated Phase (AP) who underwent HSCT between 1990 and 2018.
• Assessment of overall survival (OS), progression-free survival (PFS), non-relapse mortality (NRM), and relapse incidence (RI) at 15 years.
• Identification of prognostic factors including graft CD34+ count, donor age, disease phase (BC vs. AP), stem cell source (peripheral blood vs. bone marrow), and transplant year.

Main Results:

• At 15 years post-HSCT, OS was 34% and PFS was 26%.
• Adverse risk factors for OS and PFS included low graft CD34+ count, donor age >36 years, and CML in BC.
• Non-Relapse Mortality (NRM) was 28% and Relapse Incidence (RI) was 43% at 15 years. Peripheral blood stem-cell transplantation (PB-HSCT) and HSCT after 2008 were associated with lower NRM.
• Family donor and patient age >39 years were linked to higher RI.

Conclusions:

• Allogeneic HSCT can achieve long-term survival in patients with advanced CML.
• Optimizing graft CD34+ dose, selecting younger donors (≤36 years), and avoiding HSCT in the BC phase improve survival outcomes.
• Understanding these risk factors is crucial for improving HSCT strategies in advanced CML.