ACUTE MYELOID LEUKEMIA (AML),

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1 1 ACUTE MYELOID LEUKEMIA (AML), ALSO KNOWN AS ACUTE MYELOGENOUS LEUKEMIA WHAT IS CANCER? The body is made up of hundreds of millions of living cells. Normal body cells grow, divide, and die in an orderly fashion. During the early years of a person's life, normal cells divide faster to allow the person to grow. After the person becomes an adult, most cells divide only to replace worn-out or dying cells or to repair injuries. Cancer begins when cells in a part of the body start to grow out of control. There are many kinds of cancer, but they all start because of out-of-control growth of abnormal cells. Cancer cell growth is different from normal cell growth. Instead of dying, cancer cells continue to grow and form new, abnormal cells. Cancer cells can also invade (grow into) other tissues, something that normal cells cannot do. Growing out of control and invading other tissues are what makes a cell a cancer cell. Cancer cells often travel to other parts of the body where they begin to grow and form new tumours that replace normal tissue. This process is called metastasis. It happens when the cancer cells get into the bloodstream or lymph vessels of our body. No matter where a cancer may spread, it is always named for the place where it started. For example, breast cancer that has spread to the liver is still called breast cancer, not liver cancer. Likewise, prostate cancer that has spread to the bone is metastatic prostate cancer, not bone cancer. Not all tumours are cancerous. Tumours that are not cancer are called benign. Benign tumours can cause problems they can grow very large and press on healthy organs and tissues. But they cannot grow into (invade) other tissues. Because they can t invade, they also can not spread to other parts of the body (metastasise). These tumours are almost never life threatening and once surgically removed rarely recur. 1

2 2 is a cancer of the myeloid line of blood cells, characterized by the rapid growth of abnormal white blood cells that accumulate in the bone marrow and interfere with the production of normal blood cells. AML is the most common acute leukemia affecting adults. The symptoms of AML are caused by replacement of normal bone marrow with leukemic cells, which causes a drop in red blood cells, platelets, and normal white blood cells. These symptoms include fatigue, shortness of breath, easy bruising and bleeding, and increased risk of infection. AML is treated initially with chemotherapy aimed at inducing a remission; patients may go on to receive additional chemotherapy or a hematopoietic stem cell transplant. Recent research into the genetics of AML has resulted in the availability of tests that can predict which drug or drugs may work best for a particular r patient, as well as prognosis. SIGNSS AND SYMPTOMS Diffusely swollen gums due to infiltration by leukemic cells Most signs and symptoms of AML are caused by the replacement of normal blood cells with leukemic cells. A lack of normal white blood cell production 2

3 3 makes the patient susceptible to infections; while the leukemic cells themselves are derived from white blood cell precursors, they have no infection-fighting capacity. A drop in red blood cell count (anemia) can cause fatigue, paleness, and shortness of breath. A lack of platelets can lead to easy bruising or bleeding with minor trauma. The early signs of AML are often vague and non-specific, and may be similar to those of influenza or other common illnesses. Some generalised symptoms include fever, fatigue, weight loss or loss of appetite, shortness of breath, anemia, easy bruising or bleeding, (flat, pin-head sized spots under the skin caused by bleeding), bone and joint pain, and persistent or frequent infections. Enlargement of the spleen may occur in AML, but it is typically mild and asymptomatic. Some patients with AML may experience swelling of the gums because of infiltration of leukemic cells into the gum tissue. CAUSES A number of risk factors for developing AML have been identified, including: other blood disorders, chemical exposures, ionizing radiation, and genetics. CHEMICAL EXPOSURE Exposure to anti-cancer chemotherapy can increase the risk of subsequently developing AML. The risk is highest about 3 5 years after chemotherapy. RADIATION Ionizing radiation exposure can increase the risk of AML. Survivors of the atomic bombings of Hiroshima and Nagasaki had an increased rate of AML as did radiologists exposed to high levels of X-rays prior to the adoption of modern radiation safety practices. 3

4 4 GENETICS A hereditary risk for AML appears to exist. There are numerous reports of multiple cases of AML developing in a family at a rate higher than predicted by chance alone. The risk of developing AML is increased threefold in first-degree relatives of patients with AML. DIAGNOSIS The first clue to a diagnosis of AML is typically an abnormal result on a complete blood count. While an excess of abnormal white blood cells is a common finding, and leukemic blasts are sometimes seen, a definitive diagnosis usually requires an adequate bone marrow aspiration and biopsy. The diagnosis and classification of AML can be challenging, and should be performed by a qualified hematologist. TREATMENT Treatment of AML consists primarily of chemotherapy, and is divided into two phases: induction and post remission (or consolidation) therapy. The goal of induction therapy is to achieve a complete remission by reducing the amount of leukemic cells to an undetectable level; the goal of consolidation therapy is to eliminate any residual undetectable disease and achieve a cure. RELAPSED AML For patients with relapsed AML, the only proven potentially curative therapy is a stem cell transplant Patients with relapsed AML who are not candidates for stem cell transplantation, or who have relapsed after a stem cell transplant, may be offered treatment in a clinical trial, as 4

5 5 conventional treatment options are limited. Since treatment options for relapsed AML are limited, another option which may be offered is palliative care. PROGNOSIS Acute myeloid leukemia is a curable disease; the chance of cure for a specific patient depends on a number of prognostic factors. OVERALL EXPECTATION OF CURE Cure rates in clinical trials have ranged from 20 45%; however, it should be noted that clinical trials often include only younger patients and those able to tolerate aggressive therapies. The overall cure rate for all patients with AML (including the elderly and those unable to tolerate aggressive therapy) is likely lower. V CARE INFORMATION RESOURCE V Care provides helpful booklets about Cancers, their treatments and coping with side effects. These include Chemotherapy, Radiation Therapy, and Diet for Cancer patients. At any stage of disease, supportive care is available to relieve the side effects of treatment and to ease emotional concerns. For further information you can meet with our volunteers or call us on our toll free helpline