Can a CMML Risk Score Change Over Time? What to Know

Yes, your estimated risk category for chronic myelomonocytic leukemia (CMML) can change over time based on new test results, even if your underlying diagnosis remains the same ^[1]. Because CMML is a dynamic disease, your medical team may reassess your condition at key clinical decision points.

However, it is important to understand that a risk score is a tool used to estimate outcomes for groups of people—it does not predict exactly what will happen to you individually ^[2]. Furthermore, a change in your calculated risk score does not automatically mean you need to change your treatment ^[3].

Understanding Prognostic Models

Doctors use several different prognostic scoring models to estimate CMML risk. The most common are the CPSS-Mol, the Mayo Molecular Model, and the GFM ^[4].

These models are not interchangeable, and they each use a different combination of variables:

• CPSS-Mol includes red blood cell transfusion dependence, white blood cell count, bone marrow blast percentage, cytogenetics, and specific gene mutations ^[1].
• Mayo Molecular Model includes specific mutations, absolute monocyte count, hemoglobin levels below 10 g/dL, platelet counts below 100 × 10⁹/L, and circulating immature myeloid cells ^[4].
• GFM includes age over 65, high white blood cell count, anemia, low platelets, and ASXL1 mutation status ^[4].

These models were primarily developed to assess risk at diagnosis, and they are not automatically recalculated after every routine blood test. Your doctor may choose to recalculate your score if there is a persistent, meaningful shift in your disease, rather than a temporary fluctuation ^[5].

Factors That Inform Reassessment

If your medical team decides to formally reassess your risk, they will look at specific model inputs.

Blood Counts and Transfusion Needs

Routine changes in blood counts do not always mean your CMML is progressing; they can be affected by infections, medications, or recent transfusions. However, persistent changes can alter a risk score depending on the model used. For example, crossing specific thresholds—such as hemoglobin dropping below 10 g/dL, platelets falling below 100 × 10⁹/L, or becoming dependent on red blood cell transfusions—are factors in certain models ^[4][1].

Blast Cells

Blasts are immature blood cells. By definition, a CMML diagnosis requires having fewer than 20% blasts in both your peripheral blood and your bone marrow ^[4]. (If blasts reach 20% or higher, the disease has transformed into acute myeloid leukemia, or AML).

Different models use different blast cutoffs to estimate risk. For instance, circulating blood blasts of 2% or more, or bone marrow blasts of 10% or more, are considered risk factors in some scoring systems and may prompt your doctor to evaluate you for disease progression ^[5]. A small fluctuation in your blast percentage does not automatically prove progression.

Cytogenetics

Cytogenetics refers to the physical structure of your chromosomes. It is possible to acquire new chromosome abnormalities over time. Acquiring new high-risk cytogenetic changes after your initial diagnosis is associated with a higher risk of the disease transforming into AML ^[6].

Making Sense of Genetic Mutations

When your DNA is re-tested, the report might show “new” mutations or an increased variant allele frequency (VAF), which estimates the proportion of DNA carrying a mutation. This process is known as clonal evolution ^[7].

However, genetic testing has limitations:

• A “new” mutation might simply be a newly detectable one that was previously too small for the assay to pick up, rather than a truly newly acquired clone.
• VAF is not exactly the same as the percentage of cancer cells in your body.
• Many mutations can remain perfectly stable for long periods, while others fluctuate without causing clinical symptoms ^[8].

While changes in certain pathways (like RAS mutations) are sometimes associated with disease progression ^[7], a change in a mutation profile alone is not absolute proof that your disease is worsening ^[5]. Your care team will interpret molecular results in the context of your blood counts, bone marrow findings, and physical symptoms ^[1].

Reassessment vs. Treatment Planning

A prognostic score is only one part of your current disease assessment. Symptoms like fatigue, fevers, weight loss, or an enlarged spleen are not direct inputs for most prognostic scores, but they are critical for treatment planning ^[3].

Your doctor will integrate your risk score with your overall fitness, your goals of care, and your response to past treatments when making decisions—including whether you are a candidate for a stem cell transplant ^[3][9]. Note that if your blood counts improve due to treatment, resulting in a “lower” calculated score, this reflects improved laboratory values but does not mean the underlying CMML is cured.

When to Seek Immediate Care: Do not wait for your next routine reassessment if you experience urgent symptoms. Contact your medical team or seek emergency care immediately if you develop a fever (which can indicate a serious infection), uncontrollable bleeding, severe chest pain, sudden confusion, or severe shortness of breath.