Leukemia

Leukemia Overview

Leukemia is a term that refers to cancer of the white blood cells (Also referred to as leukocytes or WBC's). A child with leukemia produces large numbers of abnormal white blood cells in their bone marrow. These abnormal white cells crowd the bone marrow and flood the bloodstream. They cannot perform their proper role of protecting the body against diseases because they are defective.

As leukemia progresses, the cancer interferes with the body's production of other types of blood cells, including red blood cells and platelets. This results in anemia, bleeding problems, and increased risk of infection caused by white cell abnormalities. 

Leukemia accounts for about 25% of all childhood cancers. With proper treatment, the chances of surviving leukemia are very good and it is highly unlikely that the disease with reoccur again. 

Types of Leukemia

There are several different types of leukemia. Leukemia is classified into two different forms:

Acute: Acute leukemia is a more rapidly developing form. In children, 98% of leukemia's are acute. Acute leukemia is also divided in to acute myelogenous leukemia (AML); depending on whether specific white blood cells called lymphyocytes (lined to immune defenses) are involved.    

Chronic: Chronic leukemia is a slower growing form. This is a very rare form of leukemia, accounting for less than 50 cases of childhood leukemia a year in the United States.

Risks

Acute lymphocytic leukemia (ALL) most commonly occurs in children between the ages 2 to 8, with a peak incidence at age 4. It can however, affect all age groups. Children have a 20-25% chance of developing ALL or AML if they have an identical twin that is diagnosed with the illness before age six. In general, non-identical twins and other siblings of children with leukemia have two to four times the average of developing the illness. Children who have inherited certain genetic problems - such as Li-Fraumeni syndrome, Down syndrome, Kleinfelter syndrome, neurofibromatosis, ataxia telangectasia, or Fanconi's anemia - have a higher risk of developing leukemia, as do children who are receiving medical drugs to suppress their immune systems after organ transplants.

Children who have received prior radiation or chemotherapy for other types of cancer also have a higher risk for leukemia, usually within the first 8 years after treatment. 

In most cases, neither parents nor children have control over the factors that trigger leukemia, although current studies are investigating the possibility that some environmental factors may predispose a child to develop the disease. Most leukemias arise from non-inherited mutations (changes) in the genes of growing blood cells. Because these errors occur randomly and unpredictably, there is currently no effective way to prevent most types of leukemia. 

To limit the risk of prenatal radiation exposure as a trigger for leukemia (especially ALL), women who are pregnant or who suspect that they might be pregnant should always inform their doctors before undergoing tests or medical procedures that involve radiation (such as X-rays). Regular checkups can spot early symptoms of leukemia in the relatively rare cases where this cancer is linked to an inherited genetic problem, to prior cancer treatment, or to use of immunosuppressive drugs for organ transplants.

Symptoms

Due to infection-fighting white blood cells being defective in children with leukemia, children may experience increased episodes of fevers and infections. 

Children may also become anemic because anemia affects the bone marrow's production of oxygen carrying red blood cells. This makes them appear pale, and they may become abnormally tired and short of breath while playing. 

Children with leukemia may also bruise and bleed very easily, experiencing frequent nosebleeds, or bleed for an unusually long time after a very minor cut or scratch. This is because leukemia destroys the bone marrow's ability to produce clot-forming platelets. 

Other symptoms of leukemia may include:

Pain in the bones or joints, sometimes causing a limp.

Swollen lymph nodes (swollen glands) in the neck, groin or elsewhere.

An abnormally tired feeling.

Poor appetite.

In about 12% of children with AML and 6% of children with ALL, spread of leukemia to the brain causes headaches, seizures, balance problems, or abnormal vision. If ALL spreads to the lymph nodes inside the chest, the enlarged gland can crowd the trachea (windpipe) and important blood vessels, leading to breathing problems and interference with blood flow to and from the heart.

Diagnosis

Doctors will perform a physical examination to check for signs of infection, anemia, abnormal bleeding, and swollen lymph nodes. The doctors will also the child's abdomen to see if there is an enlarged liver or spleen because they can become enlarged with some cancers in children. In addition to doing a physical exam, doctors will ask you about any concerns or symptoms that you may have, you and your families past medical history, any medication you are currently taking, allergies you may have, and other issues. 

After the physical exam, doctors will order a Complete Blood Count (CBC) to measure the number of white cells, red cells, and platelets in your child's blood.  A blood smear will also be examined under a microscope to check for certain specific types of abnormal blood cells that are typically seen in patients with leukemia. Blood chemistries will also be checked. 

Depending on the results of the physical exam and blood tests, children may need the following:

A bone marrow biopsy and aspiration, in which marrow samples are removed from the body for testing

A lymph node biopsy, in which lymph nodes are removed and examined under a microscope to look for abnormal cells

A lumbar puncture (spinal tap). A sample of spinal fluid is removed from the lower back and examined for evidence of abnormal cells. This shows whether the leukemia has spread to the central nervous system (brain and spinal cord).

Bone marrow or lymph node samples will be examined and additional testing will be done to determine the specific type of leukemia. In addition to these basic lab tests, cell evaluations are also generally done, including genetic studies to distinguish between specific types of leukemia, as well as certain features of the leukemia cells. Children will receive anesthesia or sedative medications for any painful procedures.

Treatment

Certain features of a child's leukemia, such as age and initial white blood cell count, are used in determining the intensity of treatment needed to achieve the best chance for cure. Although all children with ALL are treated with chemotherapy, the dosages and drug combinations may differ.

To decrease the chance that leukemia will invade the central nervous system, patients receive intrathecal chemotherapy, the administration of cancer-killing drugs into the cerebrospinal fluid around the brain and spinal cord. Radiation treatments may also be used in addition to intrathecal chemotherapy for certain high risk patients.  Afterward children need to be closely monitored by a pediatric oncologist who specializes in childhood cancer. 

After the treatment begins, the goal is to rid any evidence of cancer cells in the body, known as remission. Once remission has occurred;, maintenance chemotherapy is usually used to keep the child in remission. This is given in cycles over a period of 2-3 years to keep the cancer from reoccurring. Leukemia will almost always relapse if the additional treatment isn't given. There is a minimal chance that cancer will return in spite the chemotherapy treatments, and then other forms of chemotherapy will be necessary.  

Sometimes a bone marrow transplant will be necessary in addition to or instead of chemotherapy, depending on the type of leukemia the child has. During the bone marrow transplant, healthy bone marrow is introduced into the child's body.  

Side effects from intensive chemotherapy can occur. Hair loss, nausea, and vomiting are some of the short term effects. 

With proper treatment, the outlook of a full recovery is very high. Many forms of childhood leukemia have had a remission rate of up to 90%. All children thereafter require regular maintenance therapy and other treatments to remain cancer-free.

Facts about Leukemia

Leukemia is the most common form of pediatric cancer. It affects approximately 3,250 children each year in the US

The 5-year survival rate for children with acute lymphocytic leukemia has greatly increased over time and is now more than 85%

Contact a CCBF doctor:

If you have any questions or would like to schedule an appointment, please call 212-746-3400 to schedule a visit with Dr. Aledo.

 

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