Acute lymphoblastic leukemia

We understand how overwhelming a diagnosis of leukemia can be. Right now, you probably have a lot of questions. How dangerous is this condition? What is the very best treatment? What do we do next?

We’ve tried to provide some answers to those questions in the following pages, and our experts can explain your child’s condition fully when you meet with us.

How common is leukemia?

Leukemia is the most common form of cancer in children.

• It affects about 3,000 children each year in the United States, accounting for about 30 percent of childhood cancers.
   
• Leukemia can occur at any age, although it is most commonly seen in children who are between 2 and 6 years old.
   
• The disease occurs slightly more frequently in males than in females, and is more common in Caucasian children than in children of other races.

What causes leukemia in children?

As a parent, you undoubtedly want to know what may have caused your child’s leukemia. In nearly all cases, the cause of leukemia can’t be determined. In the majority of childhood leukemias, gene mutations and chromosome abnormalities in the leukemia cells occur by chance. The abnormalities found in leukemia cells are not found in the other cells of the body.

It’s important to understand that leukemias most often occur for no known reason. There’s nothing that you could have done or avoided doing that would have prevented the disease from developing.

What are the different types of blood cells?

There are three types of blood cells:

• white blood cells, which help fight infection
• red blood cells, which carry oxygen
• platelets, which help blood clot and stop bleeding

Acute lymphoblastic leukemia comes from a white blood cell called a lymphocyte.

What are the different types of leukemia?

In addition to acute lymphoblastic leukemia (ALL), there are other types of leukemia. The two most common other types of leukemia seen in children and adolescents are:

• acute myelogenous leukemia (AML) 
• chronic myelogenous leukemia (CML)

What’s the difference between ALL, AML and CML?

Acute lymphocytic leukemia (ALL):

• is also called lymphoblastic or lymphoid leukemia
• accounts for about 80 percent of childhood leukemias
• can occur over a short period of days to weeks
• cancer comes from a white blood cell called a lymphocyte

Acute myelogenous leukemia (AML):

• is also called granulocytic, myelocytic, myeloblastic, or myeloid leukemia
• accounts for about 20 percent of childhood leukemias
• can occur over a short period of days to weeks
• cancer comes from a type of white blood cell that is not a lymphocyte; (from a granulocyte, monocyte or megakaryocyte)

Chronic myelogenous leukemia (CML):

• is very uncommon in children
• can occur over a period of months or years

What determines what kind of leukemia my child has?

The type of leukemia (lymphoblastic or myelogenous) is determined by the stage of development of the cells when they become leukemia cells.

• All blood cells start out as hematopoietic stem cells, which means they can develop into any type of blood cell. Chronic myelogenous leukemia (rare in children) is thought to occur when cancer develops in a hematopoietic stem cell.
   
• Early on, the stem cell becomes either 1) a lymphocyte precursor cell or 2) a myeloid precursor cell. ALL occurs when a cancer develops in a lymphocyte precursor cell. AML occurs when a cancer develops in a myeloid precursor cell.

What are the symptoms of ALL?

ALL can cause a variety of symptoms in children. Keep in mind that the symptoms of ALL may resemble other, more common conditions or medical problems. Always consult your child's physician for a diagnosis.

Because leukemia is a cancer of the bone marrow, the initial symptoms are often related to abnormal bone marrow function. The bone marrow is responsible for producing normal blood cells, including the red blood cells, white blood cells and platelets. While your child may experience symptoms differently, some of the most common include:

• anemia – When your child’s bone marrow is too crowded for red blood cells to be produced, anemia is present. Your child may appear tired, pale, and may breathe faster to compensate for the decrease in his cells’ ability to carry oxygen. A blood count will show fewer than normal red blood cells.
   
• bone and joint pain – Your child may experience pain in his bones and joints. This pain is usually a result of the bone marrow being overcrowded and "full." Many children experience lower back pain or limp as a result of bone pain.
   
• bruising or petechiae– When the marrow is too crowded to allow platelets to be produced, your child may bruise more easily. You might notice petechiae, or tiny red dots, on the skin if your child has a low number of platelets. These are very small blood vessels that have "leaked" or bled. While these symptoms pose no immediate risk, they do indicate the possibility of a more serious underlying problem. A blood count will show an abnormally low number of platelets.
   
• fever– Many children with ALL have fevers that are not related to a specific infection.
   
• recurrent infections - Although there may be an unusually high number of white blood cells on your child’s blood count, these leukemic white blood cells are immature and don’t fight infection. Your child may have had several viral or bacterial infections over the past few weeks, and may show symptoms of an infection such as a fever, runny nose and cough.
   
• abdominal pain – Stomach aches may also be a symptom of leukemia. Leukemia cells can collect in your child’s kidney, liver and spleen, causing these organs to become enlarged. Pain in the abdomen may cause your child lose his appetite and lose weight.
   
• swollen lymph nodes - Your child may also have swelling in the lymph nodes under the arms, in the groin, chest and in the neck. Leukemia cells may collect in the nodes, causing swelling.
   
• dyspnea (difficulty breathing) - In some cases of ALL, leukemia cells tend to clump together in the middle of the chest (around the thymus). This may lead to pain and difficulty breathing. Wheezing, coughing and/or problems breathing requires immediate medical attention.

Questions to ask your child’s doctor

After your child is diagnosed with leukemia, you may feel overwhelmed with information. It can be easy to lose track of the questions that occur to you.

Lots of parents find it helpful to jot down questions as they arise – that way, when you talk to your child’s doctors, you can be sure that all of your concerns are addressed.

If your child is old enough, you may want to suggest that she write down what she wants to ask her health care provider, too.

Some of the questions you may want to ask include:

• What specific type of ALL does my child have?
• What symptoms might my child experience?
• How will my child’s leukemia be treated?
• Will my child need to stay in the hospital? What treatments can be given as an outpatient?
• What side effects or complications might my child experience due to treatment?
• What kind of follow-up care should my child receive? How often will she need to come in?
• What is the likelihood of cure?