Chronic myelomonocytic leukemia: myelodysplastic or myeloproliferative?

Area of Science:

• Hematology
• Oncology
• Stem Cell Biology

Background:

• Chronic myelomonocytic leukemia (CMML) is a clonal hematopoietic stem cell disease characterized by persistent monocytosis.
• WHO classification recognizes CMML's dual dysplastic and proliferative features, distinguishing CMML-1 and CMML-2 by blast percentages.
• Typically diagnosed over age 50 with male predominance, CMML presents with non-specific symptoms.

Purpose of the Study:

• To summarize the key features, diagnosis, and prognostic factors of Chronic Myelomonocytic Leukemia (CMML).
• To highlight the role of genetic mutations, particularly ASXL1, in predicting patient outcomes.
• To review current therapeutic strategies for CMML.

Main Methods:

• Review of existing literature and WHO classification guidelines for CMML.
• Analysis of prognostic indicators including cytogenetics and gene mutations (TET2, SRSF2, ASXL1).
• Evaluation of treatment modalities such as hydroxyurea, demethylating agents, and allogeneic stem cell transplantation.

Main Results:

• CMML is defined by sustained peripheral blood monocyte elevation and combines myelodysplastic and myeloproliferative features.
• ASXL1 gene mutations are the primary predictor of outcome and can be integrated into prognostic scoring.
• Median survival is approximately 3 years, with common causes of mortality including progression to acute myeloid leukemia (AML) and cytopenias.

Conclusions:

• CMML is an aggressive hematologic malignancy with significant morbidity and mortality.
• ASXL1 mutation status is a critical prognostic marker in CMML.
• While allogeneic stem cell transplantation offers a potential cure, its feasibility is limited; current treatments focus on managing symptoms and disease progression.