Chronica long-lasting disease that changes slowly over time myeloid leukaemiacancer of blood and/or blood forming tissues (CML), also known as chronic myelogenous or granulocytic leukaemia, is a rare type of cancera disease where abnormal cells split without control and spread to other nearby body tissue and/or organs that causes an overproduction of myeloid cellsthe basic structural and functional unit of all living things in the bloodthe red bodily fluid that transports oxygen and other nutrients around the body. Myeloid cells are responsible for the production of red blood cells, plateletssmall disc-shaped blood cells that clump together to form clots to stop bleeding, 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 marrowsoft, 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 infectiona condition where harmful pathogens, such as bacteria, viruses or parasites, have entered the body 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 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, metastasiswhen the cancer has spread to other parts of the body, also known as mets, and how the cancer cells look under the microscope. Stagingthe process of determining how big the cancer is, where it started and if it has spread to other areas 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 tumoura tissue mass that forms from groups of unhealthy cells has been categorised into a phase, your doctor may also recommend genetic testinga procedure that analyses DNA to identify changes in genes, chromosomes and proteins, which can be used to analyse tumour DNA to help determine which treatment has the greatest chance of success, 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 therapymedication that targets specific molecular features of cancer cells, generally including tyrosine kinase inhibitors (TKIs) such as:
- Imatinib.
- Dasatinib.
- Nilotinib.
- Ponatinib.
- Chemotherapya cancer treatment that uses drugs to kill or slow the growth of cancer cells, while minimising damage to healthy cells.
- Immunotherapya treatment that uses a person's immune system to fight cancer.
- Stem cell transplanta procedure that involves replacing unhealthy blood-forming cells (stem cells) with healthy stem cells.
- Supportive treatmentsa variety of practices and services used to help people with cancer manage their physical, emotional and practical needs, potentially including:
- Allopurinol tablets (used to drain excess uric acid caused by elevated WBCs).
- Leukapheresisa procedure used to quickly reduce dangerously high levels of white blood cells to a safer level .
- Clinical trialsresearch studies performed to test new treatments, tests or procedures and evaluate their effectiveness on various diseases.
- Palliative carea variety of practices and exercises used to provide pain relief and improve quality of life without curing the disease.
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 riskthe possibility that something bad will happen 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:
- Anaemiaa condition where there aren't enough red blood cells in the blood, causing fatigue, weakness and pale skin and affecting how the body responds to infection, which carries its own set of symptoms:
- Fatiguea state of extreme tiredness or exhaustion, can be physical or mental.
- Dizziness.
- Paleness.
- Dyspneadifficulty breathing, shortness of breath.
- Weakness.
- Frequent of persistent infections.
- Easy bruising and/or bleeding.
- Abdominal pain or discomfort, potentially caused by an splenomegalyenlargement of the spleen.
- Excessive sweating without an apparent cause.
- Unexplained weight loss/loss of appetite.
- Fever.
- Lymphadenopathyswollen lymph nodes/glands, also known as adenopathy, most commonly in the neck, underarms and/or groinarea between the abdomen and thighs.
Not everyone with the symptoms above will have cancer, but see your GP if you are concerned.
Diagnosis
If your doctor suspects you have a CML, they may order the following tests to confirm the diagnosisthe process of identifying a disease based on signs and symptoms, patient history and medical test results and refer you to a specialist for treatment:
- Physical examinationan examination of your current symptoms, affected area(s) and overall medical history.
- Blood teststesting done to measure the levels of certain substances in the blood.
- Imagingtests that create detailed images of areas inside the body tests (if the cancer is thought to have spread beyond blood and bone marrow), potentially including:
- X-raya type of medical imaging that uses x-ray beams to create detailed images of the body .
- MRI (magnetic resonance imaging)a type of medical imaging that uses radiowaves, a strong magnet and computer technology to create detailed images of the body.
- CT (computed tomography) scana type of medical imaging that uses x-rays and computer technology to create detailed images of the body.
- PET (positron emission tomography) scana type of medical imaging that uses radioactive tracers to create detailed images of the body.
- Bone marrow aspirationa procedure that involves inserting a needle into the hipbone (or the breastbone in some cases) to remove samples of solid and liquid bone marrow..
- Biopsyremoval of a section of tissue to analyse for cancer cells.
