Leukaemia

Leukaemia is a cancer which starts in blood-forming tissue, usually the bone marrow. It leads to the over-production of abnormal white blood cells, the part of the immune system which defends the body against infection.

Video: Listen to Mary Francis McMullin a Clinical Professor of Heamatology talk about what leukaemia is

Blood cells are formed in the bone marrow, the spongy tissue found inside the bones. Blood-forming stem cells divide to produce either more stem cells or immature cells that become mature blood cells over time. A blood stem cell may become a myeloid stem cell or a lymphoid stem cell.

A myeloid stem cell becomes one of three types of mature blood cells:

  • Red blood cells that carry oxygen to all tissues of the body.
  • Platelets that form blood clots to stop bleeding.
  • Granulocytes (white blood cells) that fight infection and disease.

A lymphoid stem cell becomes a lymphoblast cell and then one of three types of lymphocytes (white blood cells):

  • B lymphocytes that make antibodies to help fight infection.
  • T lymphocytes that help B lymphocytes make the antibodies that help fight infection.
  • Natural killer cells that attack cancer cells and viruses.

Leukaemia affects white blood cells and can be classified by the type of white cell affected (myeloid or lymphatic) and by the way the disease progresses (acute or chronic). Acute and chronic do not refer to how serious the disease is but to how rapidly it progresses.

What causes Leukaemia?

In most cases of leukaemia there is no obvious cause. However, it is important to understand that:

  • Leukaemia is not a condition which can be caught from someone else (contagious)
  • Leukaemia is not passed on from a parent to a child (inherited)

Risk factors:

  • Age – most forms of leukaemia are more common in older people. The main exception to this is ALL in which peak incidence is in children
  • Gender – leukaemias are generally more common in males
  • Genetics – although leukaemia is not an inherited disease, there is a slightly higher chance that close relatives of patients may develop some forms of leukaemia. The risk is still very small and there is no cause for anxiety or for screening tests
  • Chemical exposure – being exposed to some chemicals and high levels of radiation may increase the chance of developing leukaemia. These factors account for only a very small proportion of all cases
  • Some forms of leukaemia are seen more commonly in people who have other bone marrow disorders. The most common disorders which behave in this way are myelodysplastic syndrome (MDS) and the myeloproliferative neoplasms (MPN)

Signs & Symptoms

Signs and symptoms of leukaemia (and blood cancers generally are notoriously vague and non-specific). There are no specific signs or symptoms of any type of leukaemia which would allow a doctor to make a diagnosis without laboratory tests.

In all types of leukaemia, symptoms are more commonly caused by lack of normal blood cells than by the presence of abnormal white cells. As the bone marrow becomes full of leukaemia cells, it is unable to produce the large numbers of normal blood cells which the body needs. This leads to:

  • Red blood cells that carry oxygen to all tissues of the body.
  • Weakness, tiredness, shortness of breath, light-headedness, palpitations
  • Infections – due to lack of normal white blood cells
  • Infections are more frequent, more severe and last longer
  • Fever, malaise (general feeling of illness) and sweats
  • Purpura (small bruises in skin), heavy periods, nosebleeds, bleeding gums
  • Bleeding and bruising – due to lack of platelets

There are some symptoms that are only seen in certain patients or forms of leukaemia. For example, young children with ALL may complain of pain in bones or joints and, in some types of AML, the gums may be swollen by leukaemia cells in the tissues.

In lymphoid malignancies, lymph nodes (glands) may be swollen. In some forms of the leukaemia the liver may be enlarged (hepatomegaly) or the spleen (an organ of the immune system found just under the ribs on the left hand side) may be enlarged (splenomegaly).

Diagnosis

Although a doctor may suspect a patient has leukaemia based on signs and symptoms, it can only be diagnosed by laboratory tests. The results of a simple blood count will usually indicate leukaemia although, rarely, a blood count may be normal. Most patients with leukaemia will have a bone marrow sample taken to confirm the diagnosis and to help to determine exactly what type of leukaemia a patient has. More specialised tests are often done at the same time.

Usually, a chest x-ray will be taken as well as scans, to look for swollen lymph nodes, or other affected sites. Blood samples will be taken to test for any problems with the liver, kidneys or other organs. In some, but not all, types of leukaemia a sample is taken of the fluid which surrounds the brain and spinal cord – cerebrospinal fluid (CSF). This is because some kinds of leukaemia cells can get into the nervous system, which protects them from most kinds of treatment. Some blood tests and scans will be repeated to check for the response to treatment and any complications. Other tests are usually only done at diagnosis.

Staging

Staging not widely used for leukaemia, because it is spread throughout the body when first diagnosed. However, there is a staging system for CLL which is described on the CLL web page. In several types of leukaemia there are systems to classify leukaemia as high-risk, standard or low-risk. It is important to stress that this refers to the chance of a successful outcome following standard treatment. If treatment is selected according to risk group, many patients with high-risk disease will do very well. It is also, unfortunately, not always true that a patient with low risk disease will do well. The risk group is only of the factors which affects the outcome of treatment.

Treatment

If you are being treated for any type of leukaemia, you may be asked to consider taking part in a clinical trial. Clinical trials are scientific studies to find the best treatment; you can find more here.

Some patients who have leukaemia do not start treatment straight away. If patients are not being treated they have regular check-ups. This is known as “watch and wait” or “active monitoring”. This is mainly relevant for patients with CLL. Almost all patients with CML or with acute leukaemia will start treatment soon after diagnosis. Some patients with CLL will never need to receive treatment for their leukaemia.

Although patients on watch and wait do not have to deal with side effects of treatment, it can be an incredibly anxious time. If this applies to you it is important to let your healthcare team know, as they can offer support and reassurance.

Acute leukaemia is often curable with standard treatments. Chronic leukaemia is usually not curable, but treatable. Although most patients with chronic leukaemia have a good initial response to treatment the condition will sometimes come back, this is known as a relapse and it can usually be treated again, using similar treatments as were used the first time.

The main ways in which leukaemia is treated are:

  • Chemotherapy – cell-killing drugs. Steroids are normally used along with chemotherapy for lymphoid leukaemia
  • Radiation therapy – usually only for stem cell transplant or local disease e.g. in spleen
  • Targeted therapy – drugs which specifically recognise and kill leukaemia cells
  • Biological therapy – treatments which use the immune system to destroy leukaemia cells. Often these use antibodies against markers on the leukaemia – these are known as monoclonal antibodies.
  • Stem cell transplant – Younger/fitter patients may be given a stem cell transplant (bone marrow transplant). This may be done using your own healthy stem cells or stem cells from a donor. This is most commonly done for acute leukaemia if chemotherapy does not cure the disease.

Chemotherapy is the use of cell-killing drugs. These kill the cancer cells and/or stop them from dividing. Chemotherapy is usually given in blocks or ‘cycles’ of treatment. One cycle of treatment will consist of a series of doses of chemotherapy followed by a break for the healthy cells to recover.

Chemotherapy is normally given as a combination of drugs, which, for lymphoid leukaemia, will usually include steroids. Steroids used to treat lymphoid leukaemia are a laboratory-made version of chemicals naturally made by the body. They are very different from the type of steroids sometimes misused by body builders or sportsmen.

The details of the treatment will vary depending on the features of the leukaemia and the patient’s general fitness. Patients will be given a chance to discuss treatment options and detailed information on the treatment plan before it starts. The side effects of treatment vary between different types of treatment and different patients. Patients will be given detailed information about any likely side effects before treatment starts.

Questions to ask your doctor

We understand going through a blood cancer through journey can be difficult. It may help to talk to a close friend or relative about how you are feeling. Here are some questions that may be useful to ask your doctor.

  • How would I know if I had leukaemia?
  • What tests will I need to have?
  • What will the tests show?
  • How long will the results take?
  • How rare is leukaemia?
  • What sort of treatment will I need?
  • How long will my treatment last?
  • What will the side effects be?
  • Is there anything I should or shouldn’t eat?
  • Will I be able to go back to work?Where can I get help with claiming benefits and grants?
  • Where can I get help dealing with my feelings?

Further information

We have free patient information available for leukaemia patients.

You can download the booklets on our information pages here.

Alternatively, you can have the information delivered free of charge by requesting it through our resources page.