Acute Myelogenous Leukemia (AML)
Research provides hope for a cure
AML is the second-most common form of leukemia in children, after acute lymphoblastic leukemia (ALL). AML is primarily a cancer of the bone marrow and lymph nodes. Also called acute nonlymphocytic leukemia or acute myeloid leukemia, it can affect both children and adults.
The term “acute” refers to the tendency of this disease to progress rapidly. The second term in its name — myelogenous — distinguishes it from a disorder of the lymphocytes. In AML, as in other leukemias, it is the bone marrow that malfunctions as a result of disease. Normally, the bone marrow regulates production of different kinds of cells vital to proper function.
But in AML, the regulatory mechanisms go awry and the bone marrow starts producing too many immature and abnormal cells called blasts. These blasts circulate throughout the blood stream and lymph system where they disrupt normal function of organs.
Because this disease progresses so rapidly, it is imperative that aggressive treatment at a multidisciplinary medical center begin as soon as possible. Untreated, death can occur in a matter of weeks.
- AML is the second most common form of childhood leukemia.
- Remissions are often obtained, but the leukemia can recur.
- Unlike other cancers, AML does not occur in stages. Instead, it tends to be found spread throughout the bloodstream at the time of diagnosis, and may have invaded an organ. As a result of its ability to affect the whole body at once, it must be treated aggressively as soon as possible.
AML’s early symptoms mimic common diseases like the flu, so it can often go undiagnosed. Among the symptoms are:
- Bleeding or bruising easily
- Flu-like illness with malaise, fatigue, joint pain
The following tests are commonly used to diagnose AML:
- Blood test: This is the familiar needle stick in the arm to withdraw blood painlessly in a matter of minutes. Your doctor will examine the blood under a microscope for a complete blood count to assess the number of cells and determine their types and maturity levels.
- Bone marrow biopsy: If results of the blood test are not normal, bone marrow may be examined. It is extracted through a thin needle inserted into the hip, after first numbing the area with an injection. The marrow will be examined under the microscope to examine abnormal cells.
- Chromosomal analysis: This test is done on the leukemia cells to further characterize the AML.
- Spinal tap: This is done in all cases to assess whether the disease has spread to the central nervous system. A small needle is placed between the large bones of the backbone to sample the spinal fluid for cancer cells.
Common treatments for AML include:
- Chemotherapy: The most accepted and widely-used primary treatment for AML is chemotherapy. This refers to the introduction of cancer-fighting drugs into the blood stream by mouth, or through a needle into a vein or muscle. It is a “systemic” treatment - meaning it treats the whole body, or system, because the circulating blood carries the drugs throughout the entire body. In some cases, the drugs are injected through a needle placed between the bones of the backbone into the fluid surrounding the spine and brain - usually in an area of the spine - in a procedure known as “intrathecal chemotherapy.”
- Radiation: In some cases, radiation is used. This therapy relies on a beam of high-energy particles, similar to X-rays, directed at the cancer by a machine outside the body. The assault from this concentrated energy kills cells and reduces tumor size.
- Bone marrow transplantation: Replacing diseased bone marrow with healthy marrow through bone marrow transplantation (BMT) is a technique that was pioneered at the University of Minnesota. In 1968 the very first successful human blood and marrow transplant was performed here, and physicians here have since done more than 3,700. Through this technique, diseased as well as healthy marrow is killed with high doses of chemotherapy and sometimes, with radiation as well. Healthy marrow is then taken from a donor whose tissues match the patient’s tissues. This donated marrow is transplanted into a catheter, which is in a blood vessel. Marrow cells then seek the right places in the bones to replace diseased marrow. An internationally recognized leader in bone marrow transplantation, the University of Minnesota BMT program is experiencing increasing success, and its cases are being studied in clinical trials.
- Cord blood transplantation: University of Minnesota physicians are among the few in the world who perform this treatment. In this procedure, diseased marrow is killed with drugs and radiation. Then it is replaced by healthy marrow that the patient grows with the help of blood-making cells, called stem cells. The stem cells are harvested from an umbilical cord of a newborn baby. (The primary treatment tends to be chemotherapy, sometimes followed by bone marrow transplant. In certain cases, radiation therapy may be used.)
- Additional treatments: Biological, or immunotherapy is a new approach that tries to stimulate the body’s ability to fight disease and is used in clinical trials.
- Remission induction chemotherapy: This is the first stage of treatment. Anti-cancer drugs are used to kill as many of the leukemia cells as possible to cause the cancer to go into remission. It lasts about 1 month.
- Consolidation: This is a preventive therapy to stop the spread of the cancer to the brain and spinal cord, even if none is detected there. It consists of intrathecal and/or high-dose systemic chemotherapy. Radiation therapy to the brain may also be given for this purpose. CNS prophylaxis also may be given in combination with the following treatment phase. Length of this phase varies, generally 1-2 months.
- Intensification therapy:This begins once a child goes into remission. It consists of high doses of chemotherapy intended to kill any remaining leukemia cells. It may be given one or two times, lasting about 2 months each time. The entire therapy takes approximately 9 months.
Treatment by stage
AML patients fall into one of four groups, or stages. The stage they are in determines the general approach to treatment. The stages and their treatments are:
The patient has never had leukemia before or been treated for it. Chemotherapy using two or more drugs to kill cancer cells will be the primary treatment. Intrathecal chemotherapy and radiation to the brain may also be given.
This means treatment for leukemia has been given, and that the number of white cells is within normal ranges. Chemotherapy to the Central Nervous System may also be given as a protection against possible spread.
The leukemia was treated once and has now come back. Treatment depends on the type of treatment received before. You may want to consider a clinical trial to receive promising new treatments under study.
The treatment did not eliminate the leukemia and the disease is still present.
This information is displayed with permission of the University of Minnesota Cancer Center. For more information about this disease or to review active clinical trials, please visit the Cancer Center’s website.