Leukaemia is the most common childhood cancer and affects approximately 500 children every year in the UK. It is a cancer of the blood, and affects the body's white blood cells (leukocytes). It happens when the body's bone morrow produces abnormal white blood cells in a large quantity.
Because of their abnormality, the white blood cells cannot perform their normal function of protecting the body against disease, which has severe consequences.
Additionally, as leukaemia progresses, the white blood cells also begin to interfere with the body's other functions, including the production of red blood cells and platelets. These become unable to perform their vital functions.
Leukaemia falls into two forms, comprising lymphoblastic (lymphoid) leukaemia, and myeloid leukaemia. These two forms fall into two categories - acute, which means the disease will progress quickly; and chronic, meaning that the cancer will progress slowly.
The most common form of leukaemia is acute lymphoblastic leukaemia, which accounts for 80 per cent of childhood leukaemia cases. Acute myeloid leukaemia accounts for most of the remaining cases, while chronic myeloid leukaemia accounts for just three per cent of cases. Chronic lymphoblastic leukaemia does not present itself in childhood leukaemia.
Treatments for leukaemia have advanced to the point where four out of five children will now survive the disease. These treatments include chemotherapy; radiotherapy; surgery; bone marrow transplants and stem cell transplants, a process which replaces damaged stem cells in bone marrow with new, healthy stem cells.