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My Child Has:
Chronic Myelogenous Leukemia
Programs that treat this condition
 Stem Cell Transplantation    Leukemia  
What is chronic myelogenous leukemia (CML)?
Leukemia is cancer of the blood. It develops in the bone marrow, the soft, spongy center of the long bones that produces the three major blood cells: white blood cells to fight infection; red blood cells that carry oxygen; and platelets that help blood clot and stop bleeding.

When a child has leukemia, the bone marrow, for an unknown reason, begins to make white blood cells that do not mature correctly, but continue to reproduce themselves. Normal, healthy cells only reproduce when there is enough space for them to fit. The body can regulate the production of cells by sending signals when to stop. With leukemia, these cells do not respond to the signals to stop and reproduce, regardless of space available.

These abnormal cells reproduce very quickly and do not function as healthy white blood cells to help fight infection. When the immature white blood cells, called blasts, begin to crowd out other healthy cells in the bone marrow, the child experiences the symptoms of leukemia (i.e., infections, anemia, bleeding).

Chronic myelogenous leukemia (CML) is uncommon in children. Chronic myelogenous leukemia is a leukemia in which too many immature white blood cells are produced in the marrow. The white cells normally fight infection. With this disease, the bone marrow makes too many of these abnormal cells that do not mature correctly. The marrow continues to produce these abnormal cells which crowd out other healthy blood cells.

Chronic myelogenous leukemia can occur over a period of months or years.

As you read further below, you will find general information about CML. If you would like to view summary information about cancer first, see the cancer overview.

Who is affected by leukemia?
Leukemia is the most common form of cancer in childhood. It affects approximately 3,000 children each year in the US, accounting for about 30 percent of childhood cancers. Leukemia can occur at any age, although it is most commonly seen in children between 2 and 6 years of age. The disease occurs slightly more frequently in males than in females, and is more commonly seen in Caucasian children than in African-American children, or children of other races.

CML is less common in children than other types of leukemia, including acute lymphoblastic leukemia (ALL) and acute myelogenous leukemia (AML)

What causes leukemia in children?
The majority of childhood leukemias are acquired genetic diseases. This means that gene mutations and chromosome abnormalities in cells occur sporadically (by chance). The immune system plays an important role in protecting the body from diseases, and possibly cancer. An alteration or defect in the immune system may increase the risk for developing leukemia. Factors such as exposure to certain viruses, environmental factors, chemical exposures, and various infections have been associated with damage to the immune system.

A specific chromosome rearrangement is found in patients with CML. Part of chromosome #9 breaks off and attaches itself to chromosome #22, so that there is an exchange of genetic material between these two chromosomes. This rearrangement changes the position and functions of certain genes, which results in uncontrolled cell growth. Other chromosome abnormalities can also be present.

What are the different types of leukemia?
In addition to chronic myelogenous leukemia (CML), there are two other main types of leukemia:
  • acute lymphoblastic leukemia (ALL) - also called lymphocytic or lymphoid, accounts for about 75 to 80 percent of the childhood leukemias. In this form of the disease, the lymphocyte cell line is affected. The lymphocytes, a type of white blood cell, normally fight infection. With acute lymphoblastic leukemia, the bone marrow makes too many immature lymphocytes and they do not mature correctly. The immature lymphocytes overproduce, thus crowding out other blood cells. In addition, these immature blood cells (blasts) do not work properly to fight infection. In some cases, these cancerous lymphocytes can affect the brain, spinal cord and other organs.
  • acute myelogenous leukemia (AML) - also called granulocytic, myelocytic, myeloblastic, or myeloid, accounts for about 20 percent of the childhood leukemias. Acute myelogenous leukemia is a cancer of the blood in which too many immature granulocytes (myeloblasts) are produced in the marrow. Mature granulocytes normally fight infection. With acute myelogenous leukemia, the bone marrow makes too many of these immature cells that do not mature correctly. The myeloblasts overproduce, thus, crowding out other blood cells. In addition, these myeloblasts do not work properly to fight infection. AML cells are found in the bone marrow and blood, and occasionally in the spinal fluid and skin. Rarely, they form solid tumors called chloromas
What are the symptoms of leukemia?
Because leukemia is cancer of the blood-forming tissue called the bone marrow, the initial symptoms are often related to irregular bone marrow function. The bone marrow is responsible for producing the body's blood cells, including the red blood cells, white blood cells, and platelets.

With CML, there are usually no symptoms in the early stages. When then do occur, your child may experience symptoms over a period of months of even years. Often, CML is discovered when a child is having a routine blood test for other reasons.

When leukemia occurs, the abnormal white blood cells (blasts) begin to reproduce very rapidly and begin crowding out and competing for nutrients and space with the other healthy cells. The following are the most common symptoms of leukemia. However, each child may experience symptoms differently. Symptoms may include:

  • general fatigue and weakness
  • recurrent infections - although there may be an unusually high number of white blood cells on a blood count of a child with leukemia, these white blood cells are immature and do not fight infection. The child may have had repetitive viral or bacterial infections over the past few weeks.
  • bone and joint pain - pain in bones and joints is another common symptom of leukemia. This pain is usually a result of the bone marrow being overcrowded and "full."
  • abdominal distress - abdominal pain may also be a symptom of leukemia. Leukemia cells can collect in the kidney, liver, and, particularly with CML, the spleen, causing enlargement of these organs. Pain in the abdomen may cause a child to have loss of appetite and weight loss.
  • swollen lymph nodes - the child may also have swelling in the lymph nodes under the arms, in the groin, chest, and in the neck. Lymph nodes are responsible for filtering the blood. Leukemia cells may collect in the nodes, causing swelling.
It is important to understand that the symptoms of leukemia may resemble other blood disorders or medical problems. These are common symptoms of the disease, but do not include all possible symptoms. Children may experience symptoms differently. Always consult your child's physician if you have concerns.
How is leukemia diagnosed?
In addition to a complete medical history and physical examination, diagnostic procedures for leukemia may include:
  • bone marrow aspiration and biopsy - marrow may be removed by aspiration or a needle biopsy under local anesthesia. In aspiration biopsy, a fluid specimen is removed from the bone marrow. In a needle biopsy, a core sample of bone and bone marrow is removed. These methods are often used together.
  • complete blood count (CBC) - a measurement of size, number, and maturity of different blood cells in blood
  • additional blood tests - may include blood chemistries, evaluation of liver and kidney functions, and genetic studies
  • lymph node biopsy - surgical removal of lymph node tissue to examine under a microscope to look for the presence of cancer cells
  • spinal tap/lumbar puncture - a special needle is placed into the lower back, into the spinal canal. This is the area around the spinal cord. Cerebral spinal fluid (CSF) is the fluid that bathes your child's brain and spinal cord. A small amount of (CSF) can be removed and sent for testing to determine if leukemia is present.
What are the treatments for CML?
Specific treatment for leukemia will be determined by your child's physician based on:
  • your child's age, overall health, and medical history
  • the stage of the disease
  • your child's tolerance for certain medications, procedures, or therapies
  • how your child's physician expects the disease to progress
  • your opinion or preference
Treatment usually begins by addressing the presenting symptoms such as anemia, bleeding, and/or infection. In addition, treatment for leukemia may include (alone or in combination) the following:
  • chemotherapy - a drug treatment that works by interfering with the cancer cell's ability to grow or reproduce. Different groups of drugs work in different ways to fight cancer cells and shrink tumors. Chemotherapy may be used alone for some types of cancer or in conjunction with other therapy such as radiation. Often, a combination of chemotherapy drugs is used to fight a specific cancer. Certain chemotherapy drugs may be given in a specific order depending on the type of cancer it is being used to treat. While chemotherapy can be quite effective in treating certain cancers, the agents do not differentiate normal healthy cells from cancer cells. Because of this, there can be many adverse side effects during treatment. Being able to anticipate these side effects can help the care team, parents, and child prepare, and, in some cases, prevent these symptoms from occurring, if possible.

    Chemotherapy is systemic treatment, meaning it is introduced to the bloodstream and travels throughout the body to kill cancer cells. Chemotherapy can be given:

    • as a pill to swallow
    • as an injection into the muscle or fat tissue
    • intravenously (directly to the bloodstream; also called IV)
    • intrathecally - chemotherapy given directly into the spinal column with a needle
  • intrathecal medications/chemotherapy - medications are inserted through a needle into the spinal cord into the area called the subarachnoid space)
  • radiation therapy - using high-energy rays (radiation) from a specialized machine to damage or kill cancer cells and shrink tumors
  • stem cell transplant - a treatment involving stem cells, a specific type of cell from which all blood cells develop. Stem cells develop into red blood cells to carry oxygen, white blood cells to fight disease and infection, and platelets to aid in blood clotting. Stem cells are found primarily in the bone marrow, but some also circulate in the blood stream.

    Treatment begins with high-dose chemotherapy (perhaps combined with radiation therapy) to destroy all of the bone marrow, stem cells and cancerous cells, in the body. Then, healthy stem cells from another person is used to help restore normal blood production in the patient with CML. The use of stem cells from another individual whose tissue is the same as, or almost the same as, the patient's is called allogeneic transplantation.

  • biological therapy - a wide range of substances that may be able to involve the body's own immune system to fight cancer or lessen harmful side effects of some treatments
  • other medications - to prevent or treat damage to other systems of the body caused by leukemia treatment, for example, medications to prevent or treat nausea
  • blood transfusions - red blood cells, platelets
  • antibiotics - to prevent/treat infections
  • continuous follow-up care - to determine response to treatment, detect recurrent disease, and manage late effects of treatment
What are the various stages of CML?
There are various stages in the treatment of CML, including the following:
  • chronic phase - there may be no symptoms of leukemia, but blast cells are discovered in the blood and bone marrow. This phase can last several months to several years.
  • accelerated phase - an increased number of blast cells are found in the blood and marrow and there is evidence normal cells are decreasing
  • blastic phase - also called a "blast crisis," during this phase more than 30 percent of bone marrow and blood cells are blast cells. Cancerous tumors may form in the bone or lymph nodes, collections of small organs found throughout the lymph system.
What is the long-term outlook for a child with leukemia?
Prognosis greatly depends on:
  • the stage of the disease.
  • disease response to treatment.
  • age and overall health of the child.
  • your child's tolerance of specific medications, procedures, or therapies.
  • new developments in treatment.
As with any cancer, prognosis and long-term survival can vary greatly from child to child. Prompt medical attention and aggressive therapy are important for the best prognosis. Continuous follow-up care is essential for the child diagnosed with leukemia. Side effects of radiation and chemotherapy, as well as second malignancies, can occur in survivors of leukemia. New methods are continually being discovered to improve treatment and to decrease side effects of the treatment for the disease.
What is the latest research on CML?
In the area of stem cell transplantation, the Dana-Farber/Children's Transplant Program is one of only eight institutions around the country that are investigating the use of umbilical cord transplantation. Also under study is a novel method for preventing graft versus host disease, a serious complication that occurs when transplanted cells do not recognize the tissues and organs of the recipient's body and react against the recipient's tissue. The result of this treatment approach, if it continues to be as successful, will be that the degree of match between donor and the recipient will not need to be particularly close, greatly increasing the pool of potential donors for each patient. This could also eliminate the need for long-term drug therapy traditionally needed to treat graft versus host disease.

Dana-Farber Cancer Institute and Children's Hospital are part of the Children's Oncology Group, a national group of pediatric oncologists who work together to carry out clinical trials in pediatric oncology patients. New drugs for CML are often available as part of research protocols through this group.

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