Acute myelogenous leukemia (AML) - adult
Definition
Acute myelogenous leukemia (AML) is a cancer of blood-forming tissues of the bone marrow. It involves the growth of immature white blood cells.
There are 8 categories of AML, categorized as M0 to M7, based on which blood cells are abnormal.
Alternative Names
AML; Acute myeloid leukemia (AML); Acute granulocytic leukemia; Acute nonlymphocytic leukemia (ANLL); Leukemia - acute myeloid (AML); Leukemia - acute granulocytic; Leukemia - nonlymphocytic (ANLL)Causes
Acute myelogenous leukemia (AML) may occur at any age, but generally occurs in people about age 65. (It may also affect children younger than age 1, but this article focuses on AML in adults.)
AML is rarely seen in people younger than 40. A 50 year old has a 1 in 25,000 chance of developing AML. A 70 year old has a 1 in 7,000 chance. The cancer is more common in men than women.
During AML, defective cells in the bone marrow multiply rapidly and replace healthy blood cells.
Bone marrow failure occurs as cancerous cells replace normal bone marrow. The bone marrow is part of the body's immune system. Problems with the immune system can make it harder for the body to fight infection. Patients with AML have an increased risk of bleeding as healthy blood cells drop. They become more prone to infection as the immune system loses its ability to fight off dangerous substances.
In most cases, a cause can not be determined. However, the following are thought to cause some types of leukemia, including AML:
- Radiation
- Dangerous chemicals such as benzene
- Certain chemotherapy drugs, including etoposide and drugs known as alkylating agents
Gene defects may also play a role in the development of AML.
You have an increased risk of AML if you have or had any of the following:
- Exposure to radiation and chemicals
- Immunosuppression following an organ transplant
- Blood disorders, including:
- Polycythemia vera
- Essential thrombocythemia
- Myelodysplasia (refractory anemia)
Symptoms
- Prolonged bleeding, bruising easily
- Bleeding gums
- Bleeding from the nose
- Menstrual periods, abnormal
- Skin rash or lesion
- Fatigue
- Fever
- Bone pain or tenderness
- Weight loss
- Swollen gums (rare)
- Shortness of breath aggravated by exercise
- Paleness
Exams and Tests
A physical examination may show signs of anemia, pallor, and bleeding. Less commonly, there may be signs of an enlarged spleen, liver, or lymph nodes.
A complete blood count (CBC) shows anemia and a low number of platelets. A white blood cell count (WBC) can be high, low, or normal.
Bone marrow aspiration will show if there are any leukemia cells.
Treatment
The goal of treatment is to kill the cancer cells with chemotherapy. Unfortunately, chemotherapy also harms normal cells. This raises the risk for side effects, such as excessive bleeding caused by low numbers of platelets and infection caused by a low white blood count. It takes several weeks for the bone marrow to recover and start producing normal cells.
Other treatment involves:
- Isolating the patient to prevent infection
- Antibiotics to treat infection
- Transfusions of platelets to control bleeding
- Red blood cell transfusions to fight anemia
After remission is achieved, further treatment called consolidation is necessary to achieve a permanent cure. Consolidation may consist of additional chemotherapy, a bone marrow transplant, or a stem cell transplant. Transplants may also be performed in those whose disease has come back.
Most of the different subtypes of AML have similar treatment. However, one form of AML, called acute promyelocytic leukemia (APL), is treated with a medicine called all-trans retinoic acid (ATRA). ATRA helps leukemia cells to grow into normal white blood cells. ATRA has increased the cure rate for this type of AML. The drug arsenic trioxide is approved for use in patients with APL who have failed treatment with ATRA or chemotherapy.
Support Groups
For additional information and resources, see cancer support group and leukemia support group.
Outlook (Prognosis)
Complete remission occurs in 70 - 80% of patients. Overall, about 33% of persons under age 65 survive free of disease at 5 years from diagnosis. This 5-year survival rate drops dramatically (4%) in those older than 65. In general, patients who are younger have a better chance of survival than older patients. This is partly due to one's ability to tolerate the strong chemotherapy medicines.
Patients who have not experienced a relapse during these 5 years are considered permanently cured, since most relapses occur within 2 years of diagnosis.
Without treatment, life expectancy is about 3 - 4 months.
Possible Complications
- Relapse of the disease
- Severe infection
- Life-threatening bleeding
When to Contact a Medical Professional
Call for an appointment with your health care provider if you develop symptoms of AML.
Call your health care provider if persistent fever or other signs of infection occur in a person with AML.
Prevention
Reduce your exposure to radiation, and protect yourself against chemicals or substances associated with the development of acute leukemia. People who work with such chemicals should wear protective gear.
American Cancer Society. Cancer Facts and Figures 2006. Atlanta, GA: American Cancer Society; 2006.
Reviewed By: Corey Cutler, MD, MPH, FRCP(C), Assistant Professor of Medicine, Harvard Medical School; Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA. Review provided by VeriMed Healthcare Network.
