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One third of all childhood cancers are leukaemia, with approximately 400 new cases occurring each year in the UK. Approximately 3 out of 4 of these cases are acute lymphoblastic leukaemia (ALL) while the remaining quarter are acute myeloid leukaemia (AML).

ALL can affect children at any age but is more common in children aged 1-4. It is also more common in boys than girls. AML can afect children of any age, and girls and boys are affected equally.

Leukaemia is a cancer of the white blood cells. All blood cells are made in the bone marrow. Bone marrow contains:

  • red blood cells, which carry oxygen around the body
  • platelets, which help the blood to clot and control bleeding
  • white blood cells, which help fight infection.

There are two different types of white blood cells: lymphocytes and myeloid cells (including neutrophils). These white blood cells work together to fight infection. Normally, white blood cells develop, repair and
reproduce themselves in an orderly and controlled way. In leukaemia, however, the process gets out of control and the cells continue to divide in the bone marrow, but do not mature.

These immature dividing cells fill up the bone marrow and stop it from making healthy blood cells. As the leukaemia cells are not mature, they cannot work properly. This leads to an increased risk of infection.
Because the bone marrow cannot make enough healthy red blood cells and platelets, symptoms such as anaemia and bruising can occur.

There are four main types of leukaemia: acute lymphoblastic (ALL), acute myeloid (AML), chronic lymphocytic (CLL) and chronic myeloid (CML). Chronic leukaemias usually affect adults and are extremely
rare in children and young people. Each type of leukaemia has its own characteristics and treatment.

CCLG Factsheet: Acute lymphoblastic leukaemia (ALL) in children

CCLG Factsheet: Acute myeloid leukaemia (AML) in children

Chronic myeloid leukaemia (CML) is an additional form of leukaemia in children which develops slowly but is extremely rare. 

Related links

Leukaemia CARE
Leukaemia & Lymphoma Research
NHS Choices: Acute myeloid leukaemia
NHS Choices: Acute lymphoblastic leukaemia 
Macmillan Cancer Support: Acute myeloid leukaemia
Macmillan Cancer Support: Acute lymphoblastic leukaemia
CLIC Sargent: Acute myeloid leukaemia
CLIC Sargent: Acute lymphoblastic leukaemia

   Download free storybook: 'Joe has Leukaemia'
   (CLIC Sargent publication)

   (Disclaimer: This is not a CCLG publication and we hold no responsibility for external links)