Leukemia is a cancer that affects the blood and bone marrow. Leukemia start in the bone marrow where developing blood cells, usually developing white cells, undergoes a malignant change. They multiply in an uncontrolled way and crowd the marrow, affecting its ability to make normal blood cells. Increasing numbers of abnormal cells, called blast cells or leukemic blasts eventually spill out of the bone marrow and travel around the body in the bloodstream.
Leukemia is broadly classified by how quickly the disease develops, and by the type of blood cell involved.
- Acute leukemia develops quickly and need to be treated urgently.
- Chronic leukemia develops more slowly and may not need to be treated for some time after they are diagnosed.
- Myeloid leukemia arises in immature blood cells called myeloblasts.
- Lymphoid leukemia arise in immature blood cells called lymphoblast
Therefore there are four main types of leukemia:
- Acute myeloid leukemia (AML)
- Acute lymphoblastic leukemia (ALL)
- Chronic myeloid leukemia (CML)
- Chronic lymphocytic leukemia (CLL)
In most cases, the cause of leukemia remains unknown, but there are likely to be a number of factors involved. Like all cancers, leukemia may result from damage to (or mutation of) special proteins called genes that control the growth and division of cells. In a small number of cases, exposure to high levels of radiation and particular chemicals, especially benzene and some chemotherapy drugs used to treat another cancer, may be involved. Some people with pre-existing blood disorders or particular genetic disorders may have a higher chance of developing some types of leukemia.
The main symptoms of leukemia are caused by a lack of normal blood cells. Without enough red cells, normal white cells and platelets people become fatigued, more susceptible to infections and to bleeding and bruising more easily. In some cases, people with chronic leukemia don’t have any troublesome symptoms and the disease is picked up during a routine blood test.
Treatment varies depending on the exact type of leukemia a person has, their age, and their general health.
The main treatments are chemotherapy and radiotherapy. This is given to destroy the leukemic cells and allow the bone marrow to function normally again. Other types of treatment are also used.