Leukemia is the cancer of the white blood cells. It is called blood cancer in common parlance.
Types of leukemia
In acute leukemia the condition progresses rapidly unlike in chronic leukemia. Leukemia are divided into four major types:-
- Acute myeloid leukemia (AML)
- Chronic myeloid leukemia (CML)
- Acute lymphoblastic leukemia (ALL)
- Chronic lymphoblastic leukemia (CLL)
This article focuses on AML type of leukemia.
Other names for AML
Acute myeloid leukemia (AML) is also known as:
- acute myelocytic leukemia
- acute myelogenous leukemia
- acute granulocytic leukemia
- acute nonlymphocytic leukemia
Bone marrow and stem cells
Normally blood cells are produced by bone marrow. Bone marrow is a spongy material found inside the bones.
There are stem cells within the bone marrow that mature to form the blood cells. Stem cells have the ability to create other specialised cells.
These stem cells are responsible for creation of red blood cells that help carry oxygen to various parts of the body, white blood cells that form the immune system and fight off invading microbes and platelets that help in clotting and prevention of bleeding. The bone marrow produces mature forms of each of these types of cells.
What happens in AML?
In leukemia the affected bone marrow fails to release adult and mature cells and releases a large number of immature white blood cells that are known as blast cells.
These blast cells disrupt the normal balance of cells in the blood leading to shortage of red blood cells causing anemia and platelets causing bleeding tendencies.
Shortage of adult and mature white blood cells means an increased risk of infections as well.
In AML the myeloid precursors are affected and grow and proliferate in an uncontrolled manner.
Causes and risk factors for AML
Genetic and environmental causes have been cited as risk factors for AML like ALL. Environmental causes include exposure to radiation and chemicals like benzene.
Symptoms of AML
Symptoms of acute myeloid leukaemia, like ALL, usually begin slowly and then progress rapidly. The symptoms aggravate as the number of immature white blood cells in the blood increases.
Some of the symptoms include anemia or pale skin, fatigue and tiredness, breathlessness and repeated infection episodes and bruising and bleeding episodes that are frequent and unusual.
Acute leukaemia is an uncommon type of cancer. In the United Kingdom, around 7,600 people are diagnosed each year with leukaemia and of these about 2,300 people have acute myeloid leukaemia.
This cancer is more commonly seen in individuals over 65 and is uncommon in individuals under 40. The average age of a patient with AML is about 67 years.
According to the American Cancer Society's estimates for United States for 2012 there are 47,150 new cases of leukemia (all kinds) and 23,540 deaths from leukemia. Of these 13,780 new cases are estimated to be AML in adults and there are an estimated 10,200 deaths from AML.
AML is more common in males than females. The lifetime risk of getting AML for the average man is about 1 in 232; for the average woman the risk is about 1 in 278 in the United States.
Treatment and prognosis or outlook
Chemotherapy is the standard treatment for AML. Some subtypes of AML carry a poorer outlook than others. Younger people with the condition tend to have a better outcome than older people.
Reviewed by April Cashin-Garbutt, BA Hons (Cantab)