Leukaemia is cancer of the white blood cells. Acute leukaemia means the condition progresses rapidly and aggressively and requires immediate treatment.
Acute leukaemia is classified according to the type of white blood cells that are affected by cancer. There are two main types:
- lymphocytes, which are mostly used to fight viral infections
- neutrophils, which perform several functions, such as fighting bacterial infections, defending the body against parasites and preventing the spread of tissue damage
These pages focus on acute lymphoblastic leukaemia, which is cancer of the lymphocytes. The following other types of leukaemia are covered elsewhere:
Warning signs of acute leukaemia
Symptoms of acute lymphoblastic leukaemia usually begin slowly before rapidly getting severe as the number of immature white blood cells in your blood increases (see below for an explanation of this). Symptoms include:
- pale skin
- having repeated infections over a short space of time
- unusual and frequent bleeding
Read more about the symptoms of acute lymphoblastic leukaemia.
What happens in acute leukaemia
All of the blood cells in the body are produced by bone marrow. Bone marrow is a spongy material found inside the bones. It is important because it produces special cells called stem cells.
Stem cells are very useful because they have the ability to create other specialised cells that carry out important functions. The stem cells in bone marrow produce three important types of blood cells:
- red blood cells, which carry oxygen around the body
- white blood cells, which help fight infection
- platelets, which help stop bleeding
Usually the bone marrow produces stem cells which are allowed to mature into "adult" blood cells. However, in cases of acute leukaemia, the affected bone marrow begins to release a large number of immature white blood cells that are known as blast cells.
The immature white blood cells begin to rapidly disrupt the normal balance of cells in the blood. This means that the body does not have enough red blood cells or platelet cells. This can cause symptoms of anaemia, such as tiredness, and increase the risk of excessive bleeding.
Also, as the white blood cells are not properly formed they become less effective at fighting bacteria and viruses, making you more vulnerable to infection.
If you have acute leukaemia that is left untreated, you will not be able to survive because your blood supply will not function properly.
How common is acute lymphoblastic leukaemia?
Acute leukaemia is an uncommon type of cancer. About 7,600 people are diagnosed with leukaemia each year in the UK. Of these, only about 650 people have acute lymphoblastic leukaemia.
Despite being uncommon overall, acute lymphoblastic leukaemia is the most common type of cancer to affect children. Approximately 1 in every 2,000 children will develop it. About 85% of cases occur in children aged under 15, with the majority of cases developing in those between the ages of two and five years old.
The cause or causes of acute leukaemia are uncertain, but known risk factors include:
- exposure to high levels of radiation
- exposure to benzene, a chemical used in manufacturing that is also found in cigarettes
Read more information about the causes of acute lymphoblastic leukaemia.
The outlook for children with acute lymphoblastic leukaemia is usually good. Almost all children will achieve a remission (a period of time where they are free from symptoms) from their symptoms, and 85% will be completely cured.
The outlook for adults with acute lymphoblastic leukaemia is less promising as only 40% of people with the condition will be completely cured.
Treatments for acute lymphoblastic leukaemia usually involve a combination of chemotherapy and radiotherapy. In some cases, a bone marrow transplant may also be needed to achieve a cure.
Read more about the treatment of acute lymphoblastic leukaemia.
If a cure is not possible, there is a risk that the lack of healthy blood cells can make the person extremely vulnerable to life-threatening infections (due to the lack of white blood cells) or uncontrolled and serious bleeding (due to the lack of platelets).