Chronic Myeloid Leukaemia, commonly known as CML, is a type of blood cancer that starts in the bone marrow—the soft tissue inside bones where blood cells are made. CML mainly affects a group of white blood cells called myeloid cells, which normally help fight infections. But in CML, these cells grow uncontrollably and do not function as they should.
Global and Indian Prevalence
According to the GLOBOCAN 2020 data, leukaemia accounts for over 474,000 new cases and 311,000 deaths globally each year. Among these, CML represents about 15–20% of adult leukaemia cases.
In India, CML is the most common adult leukaemia, making up around 30–60% of adult cases depending on the region. It is much rarer in children, but when it occurs, it usually behaves more aggressively than in adults.
What Causes CML?
CML is not inherited. It happens due to a genetic change in the blood-forming cells. Almost all people with CML have a specific genetic abnormality called the Philadelphia chromosome, which creates a faulty gene called BCR-ABL1. This gene tells the body to produce a protein that makes abnormal cells grow too fast.
Risk Factors
CML does not usually have clear lifestyle-related risk factors like smoking or diet. However, a few things may slightly increase the risk:
- Exposure to high doses of radiation (such as during a nuclear accident)
- Age – It is more common in adults over 50
- Gender – Men are slightly more affected than women
It is important to know that for most people, there is no clear reason why they develop CML.
Signs and Symptoms
In the early (chronic) phase, many people do not feel sick and are diagnosed during routine blood tests. As the disease progresses, symptoms may appear, such as:
- Fatigue or weakness
- Unexplained weight loss
- Night sweats
- Fever
- Pain or fullness under the ribs (due to an enlarged spleen)
How is CML Diagnosed?
A Complete Blood Count (CBC) is usually the first clue. If the white blood cell count is abnormally high, further tests like bone marrow biopsy, Philadelphia chromosome testing, or BCR-ABL1 gene testing are done to confirm the diagnosis.
Phases of CML
CML progresses in three phases:
- Chronic Phase – Most patients are diagnosed here. Symptoms are mild or absent.
- Accelerated Phase – The disease becomes more active, with more abnormal cells.
- Blast Crisis – The disease behaves like acute leukaemia and is harder to treat.
Risk Stratification in CML: Why It Matters
When someone is diagnosed with CML, doctors do not just look at the blood counts and genes—they also try to estimate how aggressive the disease might be. This process is called risk stratification.
What Are the Risk Stratification Scores in CML?
Doctors use special scoring systems at the time of diagnosis to estimate how fast the CML may progress. This helps decide the intensity of treatment and monitoring. The most used risk scores include:
🔹 Sokal Score
One of the oldest and most widely used tools. It considers:
- Age at diagnosis
- Size of the spleen
- Platelet count
- Percentage of blast cells (immature white cells) in the blood
Patients are classified into:
- Low risk
- Intermediate risk
- High risk
🔹 Hasford Score (Euro Score)
An update to the Sokal score, it includes:
- Age
- Spleen size
- Platelet count
- Blast, eosinophil, and basophil percentages
This score also categorizes patients into low, intermediate, or high risk.
🔹 EUTOS Score
A simpler model that mainly uses:
- Spleen size
- Basophil count
This score helps predict early response to treatment, especially in patients receiving tyrosine kinase inhibitors (TKIs).
🔹 ELTS Score (EUTOS Long-Term Survival)
This newer score focuses on predicting long-term survival, rather than just early response. It includes:
- Age
- Spleen size
- Platelet count
- Blast percentage
It is currently one of the most preferred risk tools for newly diagnosed CML patients.
Why Should You Care About These Scores?
While the names and numbers may sound technical, these scores help your doctor:
- Choose the best drug for your specific risk category
- Estimate how closely you should be monitored
- Decide whether more aggressive treatment (like a transplant) might be needed later
Most importantly, they allow your care team to personalize your treatment plan to give you the best possible outcome.
Treatment Options
Thanks to medical advances, CML is now considered a manageable chronic condition, especially when diagnosed in the chronic phase.
1. Targeted Therapy (TKIs)
The mainstay treatment for CML is Tyrosine Kinase Inhibitors (TKIs). These drugs block the BCR-ABL1 protein and stop the cancer from growing. Common TKIs include:
- Imatinib
- Dasatinib
- Nilotinib
- Bosutinib
- Ponatinib
- Asciminib
Most patients take a TKI as tablets daily, often for life, but some may qualify for treatment-free remission if the disease stays under control for years.
2. Bone Marrow or Stem Cell Transplant
This is usually reserved for patients who do not respond to TKIs or are in advanced stages. It is a more intense treatment with potential risks, but it can be curative.
3. Chemotherapy or Immunotherapy
Traditional chemotherapy is rarely needed, but interferon-alpha, a type of immunotherapy, was used before TKIs and may still help in selected patients. Newer immunotherapy options are still under research for CML, including CAR T-cell therapy, but are not yet standard treatment.
Recent Advances in Treatment
- Second- and third-generation TKIs are now available, offering options if the first drug stops working or causes side effects.
- Treatment-free remission (TFR) is becoming a reality for some patients. If a person has a deep, sustained response for years, they might be able to stop treatment under close monitoring.
- Molecular monitoring through PCR tests helps doctors track how well the treatment is working by measuring the level of BCR-ABL1 in the blood.
Living with CML
- Regular follow-ups are crucial. Blood tests and molecular tests help keep the disease in check.
- Side effects of TKIs can include fatigue, muscle cramps, and skin rashes—but many people tolerate them well.
- Mental health support is equally important. Learning to live with a lifelong illness can be emotionally challenging, and talking to a counsellor or support group can help.
Can CML Be Prevented?
Unfortunately, since the exact cause of CML is unknown in most cases, there are no proven preventive measures. However:
- Avoiding unnecessary radiation exposure
- Prompt health check-ups for symptoms
can help in early detection and timely treatment.
Final Thoughts
At Healius Cancer and Haematology Clinics, we understand that a diagnosis of Chronic Myeloid Leukaemia (CML) can be overwhelming—not just for the patient, but for the entire family. But the good news is that CML is one of the most successfully treated forms of leukaemia today. With timely diagnosis, targeted therapies, and close monitoring, it is possible to lead a normal, healthy, and productive life.
Under the expert care of Dr. Mangesh Kamath, Medical Oncologist and Haemato-Oncologist, we provide personalized, evidence-based treatment for each patient, including access to the latest in diagnostics, targeted therapy, molecular monitoring, and comprehensive support services.
We are committed to walking with you at every step—from diagnosis through treatment and beyond—ensuring that you and your loved ones feel informed, supported, and empowered.
If you or someone you know has been diagnosed with CML, remember:
You are not alone. You are in trusted hands.
