Chronic myeloid leukemia (CML) and chronic myelomonocytic leukemia (CMML) are two different types of cancer that affect the blood and bone marrow.

In people with CML, the body creates abnormal white blood cells known as blasts. These abnormal cells may spread throughout the body and cause symptoms such as bleeding, infections, and anemia.

In people with CMML, the body produces too many monocytes, the white blood cells that help fight bacteria. The overproduction of monocytes could lead to frequent bruising, bleeding, infections, and anemia.

This article examines the differences between CML and CMML and their symptoms. We also discuss the potential causes and treatments for the conditions and how to manage them.

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Leukemia refers to cancers that affect blood cells. Leukemia can begin in the bone marrow, the tissue responsible for producing blood cells. Both CML and CMML are types of leukemia.

Although CML and CMML are blood cancers, they are separate conditions with different treatment options. The following information explores the differences between CML and CMML.


CML is known as a chronic condition as it progresses slowly over time.

The bone marrow creates atypical white blood cells called granulocytes or blasts in people with CML. These blasts reproduce quickly but lose their ability to develop into normal cells.

Blast cells gradually spread throughout the body and take the place of healthy cells. This disease progresses in three stages:

  • chronic
  • elevated
  • blast

Most people receive a diagnosis of CML during the chronic phase, and this phase is associated with the fewest symptoms. The elevated and blast phases become increasingly severe and challenging to treat.


Unlike CML, CMML leads to a growth in the number of white blood cells called monocytes. These cells can build up throughout the bone marrow and blood.

Types of white blood cells they affectgranulocytesmonocytes
CausesPhiladelphia chromosomesuspected genetic causes
Classificationchronic, elevated, blast phasesCMML-1 and CMML-2
Common treatmentsTKIs, stem cell transplant, chemotherapystem cell transplant, chemotherapy
Estimated new U.S. diagnoses8,860 per year1,100 per year

Some of the symptoms of CML and CMML are similar since they are both forms of leukemia.

CML symptoms

The most common CML symptoms may include:

While these symptoms may indicate CML, an accurate diagnosis depends on further testing. Doctors may conduct blood cell counts to check for abnormally high granulocyte levels. They may also examine the bone marrow for abnormalities.

Finally, genetic testing can help doctors determine whether a person shows a genetic abnormality that indicates the presence of CML.

CMML symptoms

Common symptoms of CMML may include:

  • fatigue
  • excessive sweating at night
  • unexplained bleeding and bruising
  • ongoing infections
  • pain in or around the bones
  • liver and spleen enlargement
  • unexpected weight loss

Some other conditions may also cause these symptoms, so a healthcare professional will need to conduct additional tests to determine the presence of CMML.

For example, a blood count test can determine whether an individual has a high number of monocytes in their blood. Bone marrow tests can look for abnormalities associated with CMML, and genetic tests can rule out other conditions such as CML.

There is limited research surrounding the causes of CML and CMML. However, scientists do have some theories regarding the causes of these conditions.

CML causes

Researchers suggest that specific genetic mutations may cause CML. Virtually all patients with CML have a mutation known as a translocation, where a piece of a chromosome breaks away and latches onto a different chromosome.

In most people with CML, a part of chromosome 9 breaks off and swaps with a part of chromosome 22. The abnormal chromosome 22 is known as the Philadelphia chromosome. However, the reasons behind this translocation are poorly understood.

Scientists have found that radiation exposure may increase the chance of developing CML and other cancers. But scientists need to conduct more research to fully understand the cause behind CML.

CMML causes

The cause of CMML is generally unknown. According to one study, over 90% of people with CMML display some type of gene mutation. But scientists do not know why specific mutations occur or which mutations are primarily responsible for the development of CMML.

The ASXL1 mutation is known to negatively affect the chances of survival for people with this disease.

The treatments for CML and CMML may include targeted therapies, surgery, and chemotherapy.

CML treatment

One of the most common CML treatments involves tyrosine kinase inhibitors or TKIs. These medications block tyrosine kinase, an enzyme that facilitates the development of blast cells. Blocking this enzyme can reduce the rapid spread of blasts throughout the body.

People with CML may also benefit from a stem cell transplant. A stem cell transplant provides people with new stem cells that can help replenish the bone marrow and regulate blood cell production.

CMML treatment

Many cases of CMML are difficult or impossible to treat. For some eligible people, stem cell transplants are the only known option for curing this condition.

Before receiving a stem cell transplant, people with CMML must first undergo chemotherapy to target and kill cancerous cells. They will then receive a transplant containing new blood cells to support bone marrow function and encourage the production of healthy blood cells.

Living with CML or CMML may feel overwhelming. But with medical support, it is possible to manage these conditions while continuing to lead a full life.

Lifestyle and dietary changes

Eating well is one of the best ways to manage CML and CMML. Good nutrition can support feelings of wellness and may even reduce time spent in the hospital.

Individuals with these conditions may also have feelings of tiredness that impact typical daily activities. Some lifestyle and dietary changes to combat fatigue may include:

  • taking quick breaks throughout the day
  • eating plenty of nutritious snacks
  • asking for help with complex tasks
  • getting regular exercise

Devoting consistent time to self-care may help manage some of the more challenging aspects of life with CML or CMML and reduce feelings of anxiety and depression.

Supportive care

Many resources are available to support an individual with either condition.

Friends and family are valuable resources for CML and CMML management. Speaking about concerns and difficulties may help a person find the necessary support. Many medical and community centers also offer support groups specifically designed for people living with cancer.

Finally, speaking with a counselor or therapist can provide relief for many people with CML or CMML. Mental health professionals can provide practical tools and strategies to manage both the physical and emotional experiences of these conditions.

Find out more about CML support groups here.

The outlook for people with CML and CMML has improved markedly over the years. Today, individuals diagnosed with these conditions have a much higher chance of successfully managing them.

Each condition’s outlook and life expectancy depend on the individual. Only a medical professional can provide personalized information about the chance someone has of making a full recovery.

CML outlook

Individuals with CML experience a median 5-year survival rate of around 70.4%. People who receive a diagnosis and treatment in the earlier stages of this disease have a higher chance of survival. Those who respond well to initial treatment also have a better chance of a full recovery.

CMML outlook

The 5-year survival rate for CMML ranges between 10–20%. This rate can vary depending on the time of diagnosis, a person’s age, and an individual’s general health.

Both CML and CMML are forms of leukemia that affect certain blood cells in the body. While CML affects granulocytes, CMML affects monocytes.

The causes of these diseases remain unclear, although researchers believe there is a genetic basis for both. Treatment options range from chemotherapy to stem cell transplants.

With the support of a qualified medical team, individuals with CML or CMML can take steps to manage and treat their conditions.