Chronic Myeloid Leukaemia (CML)

ChronicA long-lasting disease that changes slowly. myeloid leukaemia (CML), also known as chronic myelogenous or granulocytic leukaemia, is a rare type of leukaemia (cancerA disease where abnormal cells split without control and spread to other nearby body tissue and/or organs. Cancer cells can also spread to other parts of the body through the bloodstream and lymph systems. of bloodhello/blood forming tissue) that causes an overproduction of myeloid cells
• the smallest, living parts of the body. Cells work together to form or build the body
• a human is made up of millions of Cells
• Cells reproduce themselves to make sure a body stays working
• sometimes Cells can be abnormal or damaged and these can be cancer cells
in the blood. Myeloid cells are responsible for the production of red blood cells, plateletsSmall blood cells (shaped like plates) whose job it is to come together in a group(s) or clump(s) to stop bleeding when you are injured or cut., and all white blood cells except for lymphocytes (one of the main immune cells in the body).

Blood is the bodily fluid of the circulatory system that provides nutrients and oxygen to our tissues, and helps to remove waste from our bodies. There are three primary types of blood cells produced in the inner, spongy portion of the bone (bone marrowIs soft, spongy tissue found in bones that makes blood cells.) from stem cells (immature blood cells that develop into either red blood cells (RBCs), white blood cells (WBCs), or platelets). RBCs, or erythrocytes, are responsible for providing oxygen to the tissues in our body, as well as transporting carbon dioxide to the lungs to be exhaled. WBCs are responsible for fighting infectionWhere germs, bacteria or viruses that are not usually in the body, invade the body and make a person sick. and disease in the body. Platelets are blood cells that play a major role in blood clotting (or coagulation), which is an important process that helps reduce blood loss after injury.

CML causes excess blood cells to be produced, which reduces the capacity of the bone marrow to produce healthy RBCs, WBCs, and platelets. Unlike acutenew, recent, comes with an urgent or significant sense, is sudden, sharp or urgent myeloid leukaemia (AML), this disease tends to develop slowly over time.

CML is slightly more common in males, and tends to be diagnosed after the age 40 years old. However, anyone can develop this disease.

Treatment

When cancers are detected, they are staged and graded based on size, metastasisKnown as secondary cancer, it grows/spreads from the original/ primary cancer. (whether the cancer has spread to other parts of the body) and how the cancer cells look under the microscope. Staging and grading helps your doctors determine the best treatment for you.

CML is classified into three groups, which are known as phases instead of stages and grades.

Phases of CML

The three phases of CML are based on how much excess WBCs are found, as well as the accompanying symptoms you are experiencing:

Phase One – Chronic Phase

The first phase of CML is the chronic phase. Most people with CML are diagnosed in this stage, and have few (if any) symptoms. This phase is characterised by an elevated WBC count, and a low quantity of blast (immature) cells found in the blood and/or bone marrow. People in the chronic phase of CML can go several years before being diagnosed, and can have a good prognosisTo predict how a disease/condition may progress and what the outcome might be..

If left untreated, the disease can progress to accelerated and/or blast phase of disease.

Phase Two – Accelerated Phase

The second phase of CML is the accelerated phase, which occurs in rare instances. During this phase, CML progresses from a relatively stable disease to a more aggressive one. The accelerated phase is characterised by an increase of blastic cells found in blood and bone marrow, and a higher WBC count than that of the chronic phase. In some cases, patients in this phase may also develop an enlarged spleen. This phase is generally more aggressive, and may not have as good of a prognosis as chronic phase CML.

If left untreated, the disease can progress into the blast phase of disease.

Phase Three – Blast Phase

The third phase of CML is the blast phase, also known as blast crisis, and develops in very rare instances. During this phase, CML progresses rapidly and resembles AML in disease behaviour. The blast phase is characterised by a significant increase of blast cells found in the blood and bone marrow, a very high WBC count, and the development of more severe symptoms. This phase is aggressive, and may not have as good of a prognosis as chronic or accelerated phase CML.

Treatment Options

Once the tumour has been categorised into a phase, your doctor may also recommend genetic testing, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate treatment option for you.
Treatment is dependent on several factors, including age, stage/phase of disease and overall health.

Treatment options for CML may include:

• Targeted therapy, generally including tyrosine kinase inhibitors (TKIs) such as:
  • Imatinib.
  • Dasatinib.
  • Nilotinib.
  • Ponatinib.
• Chemotherapy
  • a chemical drug treatment to kill or slow-growing cancer Cells
  • these drugs are called cytotoxic drugs
  .
• Immunotherapy.
• Stem cell transplants.
• Supportive treatments, potentially including:
  • Allopurinol tablets (used to drain excess uric acid caused by elevated WBCs).
  • Leukapheresis (a procedure used to quickly reduce dangerous levels of WBCs to a safer level).
• Clinical trials.
• Palliative careLessening pain without curing the disease..

For more information on the treatment options, please refer to the Rare Cancers Australia treatment options page.

Risk factors

While the cause of CML remains unknown, the following factors may increase the likelihood of developing the disease:

• Genetic mutations – particularly of chromosomes 9 and 22, which can lead to the development of the Philadelphia (Ph) chromosome (causes the production of the enzyme tyrosine kinase, which is thought to be found in many CML patients).
• Exposure to high levels of radiation.
• Exposure to certain industrial chemicals, such as benzene, over a long period of time.
• Previous chemotherapy treatment.

Not everyone with these risk factors will develop the disease, and some people who have the disease may have none of these risk factors. See your general practitioner (GP) if you are concerned.

Symptoms

People who have chronic phase CML often present with very few (if any) symptoms of disease. As the disease progresses, potentially to the accelerated or blast phase, some of the following symptoms may appear:

• AnaemiaWhere the number of red blood cells have dropped. This can make people feel tired, breathless and unwell and affects how the body fights infection, which carries its own set of symptoms:
  • Fatigue.
  • Dizziness.
  • Paleness.
  • Shortness of breath.
  • Weakness.
• Frequent of persistent infections.
• Easy bruising and/or bleeding.
• Abdominal pain or discomfort, potentially caused by an enlarged spleen.
• Excessive sweating without an apparent cause.
• Unexplained weight loss/loss of appetite.
• Fever.
• Swollen lymphA clear fluid that moves through the body through the lymphatic system, carrying cells that fight infection. nodes, most commonly in the neck, underarms and/or groinArea between the abdomen (belly) and thighs (top of upper legs)..

Not everyone with the symptoms above will have cancer, but see your GP if you are concerned.

Diagnosis/diagnosing

If your doctor suspects you have a CML, they will order a range of diagnostic tests to confirm the diagnosisUsing medical test results, identify and name a disease and/or condition., and refer you to a specialist for treatment.

Physical examination

Your doctor will collect your overall medical history, as well as your current symptoms. Following this, they may examine your body to check for any abnormalities.

Blood tests

Blood tests are used to assessTo measure, look at and learn from. overall health and detect any abnormalities. Some of these tests may include:

• General blood test to assess overall health.
• Full blood countA test that counts red blood cells, white blood cells and platelets in the blood., which measures the levels of red blood cells, white blood cells and platelets.
• Blood chemistry and/or blood hormoneA chemical made in different body parts/organs that is sent out to other parts of the body through the bloodstream. Hormones watch over and help control how other cells or organs act. studies, which analyse the levels of certain hormones and other substances in the blood.
• Blood smears to check changes in the number, type, shape, and size of blood cells for too much iron in RBCs.

Imaging tests

The doctor will take images of your body using magnetic resonance imagingTaking images/photos of inside body parts using magnet rather than x-ray. (MRITaking images/photos of inside body parts using magnet rather than x-ray.), a computed tomography scan (CT scanA 3-D (three dimensional) x-ray pictures that gives more information than a normal x-ray.), x-rays, ultrasounds, bone scans and/or positron emission tomography (PET scanA test that uses a radioactive drug to show a picture of how your tissues and organs are working. Also known as a positron emission tomography scan.), depending on where it is suspected the cancer is. The doctor may also look at other parts of the body and look for signs of metastasis.

Bone Marrow Aspiration & Biopsy

This process involves inserting the needle into the hipbone (or the breastbone in some cases) to remove samples of solid and liquid bone marrow. These samples will then be analysed for abnormalities.

Once the location(s) of the cancer has been identified, the doctor will perform a biopsyTo take a small piece of body tissue and test it in a laboratory. to remove a section of tissue using a needle. The tissue sample will then be analysed for cancer cells, as well as the presence of the Philadelphia chromosome. This can be done by a fine needle aspiration (FNA), a core needle biopsy (CNB), or a trephine biopsy (removal of a small portion of bone for analysis).

References

• Australian Cancer Research Foundation
• Cancer Council NSW
• Leukaemia Foundation