From the Guidelines
The long-term prognosis of Chronic Myelomonocytic Leukemia (CMML) is generally poor, with a median overall survival ranging from 2 to 3 years, and overall survival rates of 30% to 40% at 5 years after allogeneic hematopoietic cell transplantation (allo-HCT) 1.
Key Factors Influencing Prognosis
- Patient's age, with a median age at diagnosis ranging from 70 to 75 years 1
- Performance status and presence of comorbidities
- Cytogenetic abnormalities and molecular mutations
- Blood counts and bone marrow blast counts
Treatment Options and Outcomes
- Allo-HCT remains the only potentially curative treatment strategy for eligible patients, with overall survival rates of 30% to 40% at 5 years 1
- Hypomethylating agents like azacitidine or decitabine can improve blood counts and quality of life, but do not definitively extend survival
- Disease progression to acute myeloid leukemia occurs in approximately 15-30% of patients, significantly worsening prognosis
Management and Monitoring
- Regular monitoring of blood counts, bone marrow examinations, and molecular testing are essential for tracking disease progression and adjusting treatment approaches accordingly
- Patient selection, timing of allo-HCT, and pretransplant strategies are critical in maximizing chances of reaching allo-HCT and improving outcomes 1
From the Research
Long-term Prognosis of Chronic Myelomonocytic Leukemia (CMML)
The long-term prognosis of CMML is generally poor, with a significant risk of leukemic transformation (~15%-20% over 3-5 years) 2, 3, 4. Several factors can influence the prognosis, including:
- The presence of certain gene mutations, such as ASXL1 and DNMT3A mutations, and the absence of TET2 mutations, which can negatively impact overall survival 2, 3, 4
- The absolute monocyte count, hemoglobin level, platelet count, and the presence of circulating immature myeloid cells 2, 3, 4
- The risk category, as determined by prognostic models such as the Mayo Molecular Model (MMM) or the CMML-specific prognostic model (CPSS-Mol) 2, 3, 4
Treatment Options and Their Impact on Prognosis
Treatment options for CMML include:
- Hypomethylating agents, such as 5-azacitidine and decitabine, which can improve overall response rates and complete remission rates, but have no impact on mutational allele burdens 2, 3, 4, 5
- Allogeneic stem cell transplant, which is the only potentially curative option, but is associated with significant morbidity and mortality 2, 3, 4, 5
- Chemotherapy, which can be used to manage symptoms and control leukocytosis, particularly in patients with higher risk disease 5
- Supportive care, which should be incorporated into the care of all patients, including transfusion support, erythropoiesis-stimulating agents, and infection prevention measures 5
Risk Stratification and Its Importance in Determining Prognosis
Risk stratification is crucial in determining the prognosis of CMML patients, as it can help identify those who are at high risk of leukemic transformation or poor survival 2, 3, 4. The MMM stratifies CMML patients into four groups: high, intermediate-2, intermediate-1, and low, with median survivals of 16,31,59, and 97 months, respectively 2, 3, 4. Accurate risk stratification can help guide treatment decisions and improve patient outcomes.