[Allogeneic stem cell transplantation for aggressive NK cell leukemia].

Area of Science:

• Hematology
• Oncology
• Immunology

Background:

• Aggressive NK cell leukemia (ANKL) is a rare, aggressive hematologic malignancy with a poor prognosis.
• Current treatment options for ANKL are limited, with a median survival of 2-3 months.
• Allogeneic stem cell transplantation (allo-HSCT) is the only potentially curative therapy for ANKL.

Purpose of the Study:

• To evaluate the outcomes of allo-HSCT in a nationwide cohort of ANKL patients.
• To identify factors influencing survival and relapse after allo-HSCT for ANKL.
• To compare the efficacy of different stem cell sources for ANKL treatment.

Main Methods:

• Nationwide retrospective analysis of 59 ANKL patients who underwent first allo-HSCT in Japan (1997-2016).
• Data collected on patient demographics, disease status at transplantation, stem cell source, and clinical outcomes.
• Statistical analysis of overall survival (OS) and cumulative incidence of relapse/progression.

Main Results:

• The 1- and 5-year OS rates were 33.9% and 27.3%, respectively.
• The 1-year cumulative incidence of relapse or progression was 55.5%.
• Patients receiving cord blood transplants showed significantly better outcomes compared to other stem cell sources. Achieving complete or partial response before allo-HSCT improved OS.

Conclusions:

• Allo-HSCT is a promising treatment for a subset of ANKL patients, offering the potential for durable responses.
• Cord blood transplantation appears to be a superior stem cell source for ANKL.
• Further large-scale studies are needed to confirm these findings in unselected ANKL populations.