Acute Myeloid Leukemia

Acute Myeloid Leukemia Introduction Leukemia is cancer of the white blood cells. The increased number of these cells leads to overcrowding of healthy blood cells. As a result, the healthy cells are not able to function properly. In acute myeloid leukemia, or AML, there are too many of a specific type of white blood cell called myeloblasts. AML is the most common type of acute leukemia in adults. This reference summary explains acute myeloid leukemia. It covers its causes, symptoms, diagnosis, and treatment options. The Blood Normal blood is made of a fluid called plasma and 3 types of cells: 1. White blood cells 2. Red blood cells 3. Platelets White blood cells, also called WBCs or leukocytes, help the body fight infection and disease. Red blood cells, also called RBCs or erythrocytes, carry oxygen from the lungs to the body s tissues. They also take carbon dioxide from the tissues back to the lungs. The red blood cells give blood its red color. Bone Marrow White Blood Cells Red Blood Platelets Platelets, also called thrombocytes, help blood to clot when a person is injured. By clotting, bleeding is controlled and the injured person does not lose excessive amounts of blood. 1

Blood cells are formed in the soft, spongy center of bones called the bone marrow. New, undeveloped blood cells are called blasts. Some blasts stay in the marrow to mature, while some travel to other parts of the body to mature. Acute Myeloid Leukemia Normally, blood cells are produced in a controlled way, as the body needs them. This process helps keep us healthy. When leukemia develops, the body produces large numbers of abnormal white blood cells. The leukemia cells usually look different from normal white blood cells. They also do not function properly. There are several different types of leukemia. Leukemia is commonly labeled by how quickly it develops and gets worse. In acute leukemia, the disease gets worse quickly. In chronic leukemia, the disease gets worse gradually. In acute leukemia, the abnormal blood cells are blasts that remain very immature and cannot carry out their normal functions. The number of blasts increases rapidly, and the disease gets worse quickly. In chronic leukemia, some blast cells are present, but in general these cells are more mature and can carry out some of their normal functions. Also, the number of blasts increases less rapidly than in acute leukemia. As a result, chronic leukemia gets worse gradually. Leukemia can also be labeled based on the type of white blood cells it affects. Acute myeloid leukemia affects a specific type of white blood cell, called myeloblasts. Acute myeloid leukemia is the most common type of acute leukemia in adults. It can also affect children. AML also has different subtypes. Most AML subtypes are based on how mature the cancer cells are at the time of diagnosis. Subtypes are also based on how different the cancer cells are from normal cells. Risk Factors It is usually impossible to specify the cause of AML in an individual patient. Doctors know factors that can increase the chances of getting AML. These are known as risk factors. 2

Exposure to high-energy radiation is a risk factor for AML. An example is the exposure to atomic radiation seen in survivors of the Hiroshima and Nagasaki bombs. Another risk factor for leukemia is long exposure to chemicals, such as benzene. Past treatment with chemotherapy or radiation therapy increases a person s risk for AML. Certain genetic conditions, such as Down syndrome, are also a risk factor for AML. Down syndrome is a disorder caused by the presence of an extra chromosome 21 and characterized by intellectual disability and distinguishing physical features. Another risk factor for AML is having a history of a blood disorder, such as myelodysplastic syndrome. In myelodysplastic syndrome, or MDS, the bone marrow doesn t make enough red blood cells, white blood cells, and platelets. MDS may progress to AML. Other risk factors for adults include: Being male Smoking, especially if you are age 60 or older Having had treatment for childhood acute lymphoblastic leukemia (ALL) in the past Other risk factors for children include: Having a brother or sister with leukemia Being Hispanic Being exposed to cigarette smoke or alcohol before birth Not everybody who has risk factors for acute myeloid leukemia develops it. Some people who have no risk factors for AML will still develop it. Symptoms Leukemia cells are abnormal cells that cannot do what normal white blood cells do. They cannot help the body fight infections. For this reason, people with leukemia often get infections and have fevers. 3

As leukemia cells increase in number, the healthy red blood cells and platelets decrease due to overcrowding. As a result, the body does not receive enough oxygen. Without enough red blood cells, a person develops a condition called anemia. Anemia causes a person to look pale and feel weak and tired. Without enough platelets, patients bleed and bruise easily. Some of the common symptoms of leukemia include: Fever or chills Weakness and fatigue Frequent infections Unintended weight loss Swollen or tender lymph nodes Easy bruising or bleeding Othe r symptoms of leukemia include: Tiny red spots under the skin, called petechiae, caused by abnormal bleeding Swollen or bleeding gums Sweating, especially at night Bone or joint pain Painless lumps in the neck, underarm, stomach, or groin Like all blood cells, leukemia cells travel through the body. Depending on where these cells gather, patients with leukemia may have a number of symptoms. Many other diseases have symptoms similar to those of AML and other types of leukemia. Make sure to see a doctor to find out what is causing your symptoms. Diagnosis If you have the symptoms of acute myeloid leukemia, your healthcare provider will try to find out if AML is the cause. Otherwise, there may be another cause of your symptoms. 4

Your healthcare provider will ask about your family medical history in addition to your own. A physical exam will be performed. Blood tests also help in diagnosing leukemia but do not diagnose the type. Your healthcare provider may test bone marrow samples to find out more. A bone marrow aspiration is one way to collect a bone marrow sample. The doctor inserts a needle into a large bone, usually the hip. Liquid bone marrow is removed through the needle. A bone marrow bio psy uses a larger needle and removes a piece of bone and marrow. AML always arises from changes that happen in the chromosomes. Chromosomes are hereditary, or genetic, materials contained within cells. Chromosomes control the growth of cells. Special blood or bone marrow tests may be done to look for these changes in the chromosomes. Further testing may be done to diagnose one type of leukemia from another. Ask your healthcare provider about additional testing you may need. Staging The extent or spread of cancer is usually described as stages. Unlike other cancers there is no standard staging system for AML. AML is described according to: Which subtype of AML a person has Whether the leukemia has spread outside the blood and bone marrow This information is used instead of the stage to plan treatment. Bone Marrow Aspiration Usually the disease is also described as untreated, in remission, or recurrent. Untreated AML is newly diagnosed and has not yet been treated. AML in remission has been successfully treated and the patient does not have symptoms. Recurrent AML is cancer that has come back after being in remission. 5

Acute myeloid leukemia can spread to other parts of the body through blood vessels and lymph channels. A spinal tap checks for leukemia cells in the fluid around the brain and spinal cord by inserting a needle into the spinal column. Another name for a spinal tap is a lumbar puncture. Chest x-rays can reveal signs of leukemia in the chest. Other imaging tests, such as a CT scan or MRI, may also be done to look for signs of cancer. A CT scan is an x-ray machine linked to a computer. A CT scan takes a series of detailed pictures of your organs. You may be given contrast material by mouth or injection to make abnormal areas easier to see. An MRI uses strong magnets to create images of the inside of the body. Spinal Tap Treatment and Supportive Care Treatment for leukemia is complex. It is not the same for all patients. Treatment for acute myeloid leukemia depends on: The extent of the disease Whether the leukemia has been treated before The patient s age, symptoms, and general health AML should be treated right away. The main goal of treatment is to stop the disease. This is also called remission. The other goal of AML treatment is to prevent it from coming back. This is called relapsing. Treatment for AML may involve chemotherapy, radiation therapy, stem cell transplant, or targeted therapy. Often some combination of these treatments is used. 6

Chemotherapy is the use of drugs to kill cancer cells. Chemotherapy is usually given in the blood stream through an IV. Sometimes it may be taken by mouth. Radiation therapy uses high-energy rays to kill cancer cells and stop them from growing and spreading. The radiation that treats the cells comes from a machine. To treat AML, the radiation may be aimed at a specific area of the body where there is a collection of leukemia cells. Other patients may receive radiation that is directed at the body as a whole. This type of radiation therapy is called total-body irradiation. It is usually given before a stem cell transplant. Stem cell transplants are another treatment option for AML. First the patient s leukemia-producing bone marrow is destroyed by high doses of drugs and radiation. It is then replaced by healthy bone marrow. Stem cells are removed from the blood or bone marrow of a donor. When the cells are taken from bone marrow, the procedure is sometimes called a bone marrow transplant. Th e donor s stem cells are given to the patient. These stem cells grow into and restore the patient s blood cells. Targeted therapy is another treatment option for AML in children. It uses drugs or other substances to identify and attack specific cancer cells without harming normal cells. Certain drugs may also be used to block an enzyme that causes the body to make more white blood cells than it needs. An enzyme is a protein that speeds up chemical reactions in the body. There may also be clinical trials available for people with AML. Clinical trials test new medical approaches and treatments. AML and its treatment can lead to other health problems. It is important to have supportive care before, during, and after cancer treatment. Supportive care is treatment to control symptoms, to relieve the side effects of therapy, and to help you cope with emotions. 7

Supportive care also deals with the pain associated with cancer and its treatments. Your healthcare provider or a pain control specialist can suggest ways to relieve or reduce pain. Summary Acute myeloid leukemia, or AML, is cancer of the white blood cells. The increased number of these cells leads to overcrowding of healthy blood cells. As a result, the healthy cells are not able to function properly. In AML, there are too many of a specific type of white blood cells called myeloblasts. AML is the most common type of acute leukemia in adults. Diagnosis often involves blood tests and bone marrow tests. Treatment options for AML include chemotherapy, radiation therapy, stem cell transplant, or targeted therapy. Often some combination of these treatments is used. AML is most treatable in its early stages. Research already has led to advances that have helped people live longer. It continues to find better ways to care for people with acute myeloid leukemia. 8