Adult Acute Myeloid Leukaemia

• Adult acute myeloid leukaemia (AML) is a type of cancer in which the bone marrow makes abnormal myeloblasts (a type of white blood cell), red blood cells, or platelets.
• There are different subtypes of AML.
• Smoking, previous chemotherapy treatment, and exposure to radiation may affect the risk of developing adult AML.
• Possible signs of adult AML include fever, feeling tired, and easy bruising or bleeding.
• Tests that examine the blood and bone marrow are used to detect (find) and diagnose adult AML.
• Once adult AML has been diagnosed, tests are done to find out if the cancer has spread to other parts of the body.
• There is no standard staging system for adult AML.
• Certain factors affect prognosis (chance of recovery) and treatment options.

Adult acute myeloid leukaemia (AML) is a type of cancer in which the bone marrow makes abnormal myeloblasts (a type of white blood cell), red blood cells, or platelets.

Adult acute myeloid leukaemia (AML) is a cancer of the blood and bone marrow. This type of cancer usually gets worse quickly if it is not treated. It is the most common type of acute leukaemia in adults. AML is also called acute myelogenous leukaemia, acute myeloblastic leukaemia, acute granulocytic leukaemia, and acute nonlymphocytic leukaemia.

Normally, the bone marrow produces stem cells (immature cells) that develop into mature blood cells. There are 3 types of mature blood cells:

• Red blood cells that carry oxygen and other materials to all tissues of the body.
• White blood cells that fight infection and disease.
• Platelets that help prevent bleeding by causing blood clots to form.

In AML, the stem cells usually develop into a type of immature white blood cell called myeloblasts (or myeloid blasts). The myeloblasts in AML are abnormal and do not mature into healthy white blood cells. Sometimes in AML, too many stem cells develop into abnormal red blood cells or platelets. These abnormal white blood cells, red blood cells, or platelets are also called leukaemia cells or blasts. Leukaemia cells are unable to do their usual work and can build up in the bone marrow and blood so there is less room for healthy white blood cells, red blood cells, and platelets. When this happens, infection, anemia, or easy bleeding may occur. The leukaemia cells can spread outside the blood to other parts of the body, including the central nervous system (brain and spinal cord), skin, and gums.

This summary is about adult AML. Refer to the following summaries for information about other types of leukaemia:

• Childhood Acute Myeloid Leukaemia/Other Myeloid Malignancies Treatment
• Chronic Myelogenous Leukaemia Treatment
• Adult Acute Lymphoblastic Leukaemia Treatment
• Childhood Acute Lymphoblastic Leukaemia Treatment
• Chronic Lymphocytic Leukaemia Treatment
• Hairy Cell Leukaemia Treatment

There are different subtypes of AML.

The AML subtypes are based on how mature (developed) the cancer cells are at the time of diagnosis and how different they are from normal cells.

Smoking, previous chemotherapy treatment, and exposure to radiation may affect the risk of developing adult AML.

Possible risk factors for AML include the following:

• Being male.
• Smoking, especially after age 60.
• Having had treatment with chemotherapy or radiation therapy in the past.
• Having had treatment for childhood acute lymphoblastic leukaemia (ALL) in the past.
• Being exposed to atomic bomb radiation or the chemical benzene.
• Having a history of a blood disorder such as myelodysplastic syndrome.

Possible signs of adult AML include fever, feeling tired, and easy bruising or bleeding.

The early signs of AML may be like those caused by the flu or other common diseases. A doctor should be consulted if any of the following problems occur:

• Fever.
• Shortness of breath.
• Easy bruising or bleeding.
• Petechiae (flat, pinpoint spots under the skin caused by bleeding).
• Weakness or feeling tired.
• Weight loss or loss of appetite.

Tests that examine the blood and bone marrow are used to detect (find) and diagnose adult AML.

The following tests and procedures may be used:

• Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.
• Complete blood count (CBC): A procedure in which a sample of blood is drawn and checked for the following:
o The number of red blood cells, white blood cells, and platelets.
o The amount of haemoglobin (the protein that carries oxygen) in the red blood cells.
o The portion of the sample made up of red blood cells.

• Blood chemistry studies: A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that produces it.
• Peripheral blood smear: A procedure in which a sample of blood is checked for the presence of blast cells, number and kinds of white blood cells, the number of platelets, and changes in the shape of blood cells.
• Bone marrow aspiration and biopsy: The removal of a small piece of bone and bone marrow by inserting a needle into the hipbone or breastbone. A pathologist views both the bone and bone marrow samples under a microscope to look for signs of cancer.
• Cytogenetic analysis: A test in which the cells in a sample of blood or bone marrow are viewed under a microscope to look for certain changes in the chromosomes.
• Immunophenotyping: A process used to identify cells, based on the types of antigens or markers on the surface of the cell. This process is used to diagnose the subtype of AML by comparing the cancer cells to normal cells of the immune system.

Once adult AML has been diagnosed, tests are done to find out if the cancer has spread to other parts of the body.

The extent or spread of cancer is usually described as stages. In adult acute myeloid leukaemia (AML), the subtype of AML and whether the leukaemia has spread outside the blood and bone marrow are used instead of the stage to plan treatment. The following tests and procedures may be used to determine if the leukaemia has spread:

• Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
• Lumbar puncture: A procedure used to collect cerebrospinal fluid from the spinal column. This is done by placing a needle into the spinal column. This procedure is also called an LP or spinal tap.
• Ultrasound exam: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs in the abdomen and make echoes. The echoes form a picture of body tissues called a sonogram.

There is no standard staging system for adult AML.

The disease is described as untreated, in remission, or recurrent.

Untreated adult AML

In untreated adult AML, the disease is newly diagnosed. It has not been treated except to relieve symptoms such as fever, bleeding, or pain and the following are true:

• The complete blood count is abnormal.
• At least 20% of the cells in the bone marrow are blast (leukaemia cells).
• There are signs or symptoms of leukaemia.

Adult AML in remission

In adult AML in remission, the disease has been treated and the following are true:

• The complete blood count is normal.
• Less than 5% of the cells in the bone marrow are blasts (leukaemia cells).
• There are no signs or symptoms of leukaemia in the brain and spinal cord or elsewhere in the body.

Recurrent Adult AML

Recurrent AML is cancer that has recurred (come back) after it has been treated. The AML may come back in the blood or bone marrow.

Certain factors affect prognosis (chance of recovery) and treatment options.

The prognosis (chance of recovery) and treatment options depend on:

• The age of the patient.
• The subtype of AML.
• Whether the patient received chemotherapy in the past to treat a different cancer.
• Whether there is a history of a blood disorder such as myelodysplastic syndrome.
• Whether the cancer has spread to the central nervous system.
• Whether the cancer has been treated before or recurred (come back).

It is important that acute leukaemia be treated right away.

Treatment Option Overview

Key Points for This Section

• There are different types of treatment for patients with adult acute myeloid leukaemia.
• The treatment of adult AML usually has 2 phases.
• Four types of standard treatment are used:
o Chemotherapy
o Radiation therapy
o Stem cell transplant
o Other drug therapy

• New types of treatment are being tested in clinical trials. These include the following:
o Biologic therapy

There are different types of treatment for patients with adult acute myeloid leukaemia.

Different types of treatment are available for patients with adult acute myeloid leukaemia (AML). Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. Before starting treatment, patients may want to think about taking part in a clinical trial. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment.

Clinical trials are taking place in many parts of the country. Information about ongoing clinical trials is available from the NCI Web site. Choosing the most appropriate cancer treatment is a decision that ideally involves the patient, family, and health care team.

The treatment of adult AML usually has 2 phases.

The 2 treatment phases of adult AML are:

• Remission induction therapy: This is the first phase of treatment. Its purpose is to kill the leukaemia cells in the blood and bone marrow. This puts the leukaemia into remission.
• Maintenance therapy: This is the second phase of treatment. It begins after the leukaemia is in remission. The purpose of maintenance therapy is to kill any remaining leukaemia cells that may not be active but could begin to regrow and cause a relapse. This phase is also called remission continuation therapy.

Four types of standard treatment are used:

Chemotherapy

Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping the cells from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the spinal column (intrathecal chemotherapy), an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). Intrathecal chemotherapy may be used to treat adult AML that has spread, or may spread to the brain and spinal cord. Combination chemotherapy is treatment using more than one anticancer drug. The way the chemotherapy is given depends on the subtype of the cancer being treated and whether it has spread to the brain and spinal cord.

Radiation therapy

Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.

Stem cell transplant

Stem cell transplant is a method of giving chemotherapy and replacing blood-forming cells that are abnormal or destroyed by the cancer treatment. Stem cells (immature blood cells) are removed from the blood or bone marrow of the patient or a donor and are frozen and stored. After the chemotherapy is completed, the stored stem cells are thawed and given back to the patient through an infusion. These reinfused stem cells grow into (and restore) the body's blood cells.

Other drug therapy

Arsenic trioxide and all-trans retinoic acid (ATRA) are anticancer drugs that kill leukaemia cells, stop the leukaemia cells from dividing, or help the leukaemia cells mature into white blood cells. These drugs are used in the treatment of a subtype of AML called acute promyelocytic leukaemia.

New types of treatment are being tested in clinical trials. These include the following:

Biologic therapy

Biologic therapy is a treatment that uses the patient's immune system to fight cancer. Substances made by the body or made in a laboratory are used to boost, direct, or restore the body's natural defenses against cancer. This type of cancer treatment is also called biotherapy or immunotherapy.

One type of biologic therapy is monoclonal antibody therapy, a cancer treatment that uses antibodies made in the laboratory from a single type of immune system cell. These antibodies can identify substances on cancer cells or normal substances that may help cancer cells grow. The antibodies attach to the substances and kill the cancer cells, block their growth, or keep them from spreading. Monoclonal antibodies are given by infusion. They may be used alone or to carry drugs, toxins, or radioactive material directly to cancer cells.

Treatment Options for Adult Acute Myeloid Leukaemia

Untreated Adult Acute Myeloid Leukaemia

Standard treatment of untreated adult acute myeloid leukaemia (AML) during the remission induction phase depends on the subtype of AML and may include the following:

• Combination chemotherapy.
• High-dose combination chemotherapy.
• Stem cell transplant using donor stem cells.
• All-trans retinoic acid (ATRA) plus chemotherapy.
• Intrathecal chemotherapy.

Information about ongoing clinical trials is available from the NCI Web site.
Adult Acute Myeloid Leukaemia in Remission

Standard treatment of adult AML during the remission phase depends on the subtype of AML and may include the following:

• Combination chemotherapy.
• High-dose chemotherapy, with or without radiation therapy, and stem cell transplant using the patient's stem cells.
• High-dose chemotherapy and stem cell transplant using donor stem cells.

Information about ongoing clinical trials is available from the NCI Web site.
Recurrent Adult Acute Myeloid Leukaemia

There is no standard treatment for recurrent adult AML. Treatment depends on the subtype of AML and may include the following:

• Combination chemotherapy.
• Biologic therapy with monoclonal antibodies.
• Stem cell transplant.
• Arsenic trioxide therapy