About chronic myeloid leukaemia (CML)
In CML, the bone marrow makes too many white blood cells called granulocytes. This is caused by a genetic abnormality called the Philadelphia chromosome. This abnormality forms when parts of chromosome 9 and 22 swap places, creating a new gene called BCR-ABL1. This gene makes an enzyme called tyrosine kinase, which normally helps control cell growth.
In CML, the tyrosine kinase enzyme is always active, causing the bone marrow to make too many abnormal white blood cells. This means there is very little space for normal healthy blood cells. A shortage of red blood cells, platelets, and healthy white blood cells can lead to anaemia, bleeding, bruising, and frequent infections.
CML usually develops gradually and progresses slowly over weeks or months. It has three phases:
Chronic myeloid leukaemia (CML) versus chronic myelomonocytic leukaemia (CMML)
CML and CMML have similar names, but they are different blood cancers. They affect different types of white cells.
- CML is a type of blood cancer caused by a specific genetic change called the Philadelphia chromosome.
- CMML is a rare blood cancer that has features of both myelodysplastic syndrome (MDS) and myeloproliferative neoplasms (MPN).
- CML usually responds well to treatment with tyrosine kinase inhibitors (TKIs), a targeted therapy.
- CMML can be more difficult to treat.
- Both CML and CMML can progress into a more aggressive blood cancer, acute myeloid leukaemia (AML).
- Survival rate five years from diagnosis is 86% for CML and 40% for CMML.
Symptoms of chronic myeloid leukaemia (CML)
Because CML develops slowly, many people don’t have any symptoms. This is often the case in the early stages, and the disease is picked up on a routine blood test.
Common symptoms of CML include:
- feeling tired for no reason
- night sweats
- breathlessness
- unintentional weight loss
- fever without infection
- pain or full feeling in the abdomen.
Causes of chronic myeloid leukaemia (CML)
Chronic myeloid leukaemia (CML) is not an inherited condition and cannot be passed down from parents to their children. It develops because of a genetic mutation that occurs in blood forming cells during a person’s lifetime. In most cases, there is no known or specific cause for this mutation.
There are some risk factors that increase you risk of developing CML, such as:
- age, it is more common in people over 60 years old
- gender, it is more common in males
- exposure to high dose radiation.
Stages of chronic myeloid leukaemia (CML)
CML is classified into three phases (also called stages).
- Most people are diagnosed in chronic phase.
- This phase features a high white blood cell count with only a small number of blast cells (less then 5%).
- If untreated, chronic phase CML will eventually progress to accelerated and/or blast phase.
- You usually don’t have many symptoms.
- In accelerated phase there is an increase in your blast cell count in the blood and bone marrow.
- About 5% of patients with chronic phase CML will progress to accelerated phase.
- If untreated, accelerated phase CML will eventually progress to blast phase CML.
- You will experience some symptoms.
- Blast phase CML is the most aggressive phase.
- There is a significant increase in your blast cell count.
- It is likely that CML has spread to tissues and organs.
- This phase can look like acute myeloid leukaemia (AML) or acute lymphoblastic leukaemia (ALL).
- You will experience more symptoms.
Diagnosis of chronic myeloid leukaemia (CML)
CML is diagnosed with a number of tests. You may have some or all these tests.
A bone marrow biopsy is the best test to diagnose CML. A bone marrow biopsy uses a needle to take a sample of bone marrow, usually from the back of the hip. A small amount of liquid bone marrow is removed and sent to the lab for testing. Often, a tiny piece of the bone itself is also taken to be examined.
Blood tests are taken:
- at diagnosis (baseline bloods) and throughout treatment
- to see if CML is affecting your blood cells, electrolytes, or other organs such as the liver or kidneys.
Genetic tests look for faults in the cancer cells. In CML, they are looking for the Philadelphia chromosome and other genetic mutations. These tests are done from blood and bone marrow samples. You don’t need an extra test
The tests are called FISH (fluorescence in situ hybridisation) and PCR (polymerase chain reaction).
Other tests you may have include:
- medical history and physical exam
- computed tomography (CT) scan
- ultrasound
- magnetic resonance imaging (MRI).
These tests help your treatment team work out your stage and prognosis, or if CML is affecting other organs.
Fertility and chronic myeloid leukaemia (CML)
Some treatments for CML can affect fertility.
For women they can cause damage to the ovaries.
For men it is possible to have low or abnormal sperm production.
Your fertility may become normal again in the future, but it is difficult to predict.
It is important to ask your doctor about your risk of infertility as early as possible. There are some options for preserving fertility. Decisions about what options might be right for you usually need to be made before you start treatment.
Standard treatments for CML do not usually cause permanent infertility. However, you should discuss this with your treatment team if you plan to conceive.
You can read more about Fertility support on our webpage.
Treatment for chronic myeloid leukaemia (CML)
The type of treatment you receive for your CML depends on the phase of the leukaemia. Most people are treated with targeted therapy in the form of an oral tablet.
However, your haematologist will consider many factors when discussing a treatment plan with you, including:
- your phase of CML
- your overall health
- your age
- your wishes.
Targeted therapy is a cancer treatment that finds and blocks parts of cancer cells that help them grow and spread. This is the most common treatment for CML.
Cancer growth inhibitors called tyrosine kinase inhibitors (TKIs) are a targeted therapy used to treat CML. Tyrosine kinase is an abnormal protein that is produced by the Philadelphia chromosome. This protein tells leukaemia cells to grow and multiply quickly. TKIs aim to block this protein and stop the leukaemia cells from growing and multiplying. TKIs are given as oral tablets.
Clinical trials may be available for some people with CML. They often compare new or combination therapies with current treatments, including side effects.
Many are randomised, meaning some patients receive the new treatment, and others receive standard care. Trials help improve future treatments and may offer access to costly new therapies not on the Pharmaceutical Benefits Scheme (PBS) in Australia.
If you are considering a clinical trial, your doctor will explain:
- the possible risks and benefits
- how it compares to standard treatment
- what is involved.
You will need to give informed consent before taking part.
It is possible you may be offered chemotherapy or a stem cell transplant as part of your treatment plan for CML. You can read more about these treatment types on our webpages, Chemotherapy for blood cancer | Leukaemia Foundation and Stem cell transplants | Leukaemia Foundation
Survival rate for chronic myeloid leukaemia (CML)
The survival rate of CML ranges from 55% (for older people) to 90% (for younger people), 5 years from diagnosis. Survival rate is a population based measure. Whereas your individual prognosis takes into account factors that can impact survival rate.
Your prognosis is estimated by your haematologist. It is a prediction of the likely course and outcome of your disease. The factors considered when discussing your prognosis include:
- your phase of disease
- your overall health
- your age.
Your prognosis might change if your CML progresses, comes back or does not respond to treatment.
Follow-up care for chronic myeloid leukaemia (CML)
You will need regular checkups with your treatment team once you have commenced treatment for your CML. This is to check on how the CML is tracking and any long lasting side effects from the treatment. If you notice any symptoms of your CML returning after you commence treatment, you should tell your treatment team as soon as possible. You may need tests if you have symptoms to check the leukaemia isn’t progressing. It is possible that you may require a change of treatment to keep the leukaemia under control.
Living with chronic myeloid leukaemia (CML)
Life after a blood cancer diagnosis can be different. Regular appointments, including follow-up care and tests, may be tiring or stressful. Your priorities and everyday life may also change.
You may need support with your:
- physical and emotional wellbeing
- relationships
- exercise and nutrition
- finances and returning to work or study.
Everyone responds differently to cancer and treatment. There is no right or wrong way to cope. There are some helpful resources and information to guide you on our Living well with blood cancer webpage.
Politeness is bad for your health
The Leukaemia Foundation has partnered with Novartis to create a free CML symptom and treatment tracker for those diagnosed with CML to help you have better conversations with your doctor.
A Chronic Disease Management (CDM) plan is a service provided under Medicare to help you manage long-term health conditions like CML. It’s created with your GP to assist with appropriate support. Regular GP visits under the plan allow for close monitoring of symptoms, medication side effects, or changes in health. The GP can help manage other conditions that may arise or be affected by CML or its treatment (like infections, fatigue, or bone health).
Additionally, a CDM plan means CML patients can access up to 5 Medicare rebated allied health visits per year. This might include:
- psychologists to support mental health and coping with a cancer diagnosis
- dietitians to help manage side effects of treatment
- physiotherapists or exercise physiologists for fatigue or physical strength.
Caring for someone with chronic myeloid leukaemia (CML)
We have a range of information and resources that may help when you are caring for someone with chronic myeloid leukaemia (CML).
Resources for CML
Booklet to download:
Optimal Care Pathway for CML
An Optimal Care Pathway for CML has been developed in association with the Cancer Council, Australia and you can access it below.
Your Guide to Best Cancer Care – for chronic myeloid leukaemia (CML) patients
A guide to help you, your family, and friends as you navigate through the healthcare system
References
- Chronic myeloid leukemia (CML): symptoms, treatment & prognosis, Cleveland Clinic
- Staging & prognosis for chronic myeloid leukaemia (CML) , Cancer Council NSW
- Signs and symptoms of CML, American Cancer Society
- Tests for CML, American Cancer Society
- Chronic Myeloid Leukemia Treatment, National cancer institute
- Chronic myeloid leukaemia, eviQ
- Survival for chronic myeloid leukaemia (CML), Cancer Research UK
