Childhood Leukemia

What is childhood leukemia?
Leukemia is the most common cancer that affects children. It is a cancer of the blood cells and the tissue that creates bloods cells, such as the bone marrow.

In a healthy person, blood cells form in the bone marrow as stem cells and later mature into different types of blood cells (such as red blood cells, white blood cells, or platelets) and move into the bloodstream. In a person with leukemia, the bone marrow starts producing many abnormal blood cells, which enter the blood stream and start crowding out the normal, healthy blood cells. The abnormal blood cells prevent the normal blood cells from functioning and doing their job properly.

Types of leukemia
There are a few different types of leukemia. Leukemia can be acute or chronic.

Acute leukemia develops and worsens very quickly. It can be very life-threatening. The bone marrow starts to produce high numbers of immature (underdeveloped) white blood cells called blasts that enter the bloodstream. These immature blood cells quickly crowd out the normal blood cells in the bloodstream and do not function properly enough to fight infection and bleeding or prevent anemia in the body, making the body extremely weak and vulnerable. 

The two most common types of acute leukemia are:
• Acute lymphoblastic leukemia (ALL)
• Acute myelogenous leukemia (AML)

Chronic leukemia is slow-developing and worsens gradually. Symptoms may take a while to appear. Sometimes chronic leukemia is diagnosed (for example during a routine check-up) before symptoms even appear. This is because the leukemia cells are usually developed enough to function like normal white blood cells at first, before they start to gradually worsen.

There are two main types of chronic leukemia:
• Chronic Myelogneous Leukemia (CML)
• Chronic Lymphocytic Leukemia (CLL)

What causes leukemia?
In most cases of childhood leukemia, there is no apparent cause for the development of the disease.

How is childhood leukemia diagnosed?
If KHCC doctors suspect that a child has leukemia, they will perform some of the following procedures to correctly diagnose and stage (determine how far it has spread) the disease:

• Blood tests:  among the most frequently tests done are complete blood count (CBC), kidney function test, liver function test and uric acid level determination. Also, microscopic examination of a blood smear is necessary to check for the presence of malignant cells (blasts)
• Bone marrow biopsy is the most commonly used test to determine the type of leukemia
• Spinal tap to check for malignant cells in the cerebrospinal fluid (CSF), the fluid that fills the spaces in and around the brain and spinal cord
• Cytogenic analysis (where the lab looks at the chromosomes of cells from samples of blood, bone marrow, or lymph nodes) to determine if significant genetic problems exist. For example, people with CML have an abnormal chromosome called the Philadelphia chromosome
• Molecular diagnostics (PCR and FISH tests). PCR tests are able to detect minute traces of cancer cells in the body while FISH tests detect any chromosomal defects in a cell’s DNA.

How is childhood leukemia treated at KHCC?
At KHCC, the treatment plan for a patient with childhood leukemia is determined by a multidisciplinary team of specialists. The treatment plan depends on many factors, such as the patient’s age, and the stage of the disease. Doctors at KHCC ensure that patients receive the most effective treatment that responds best to their particular case.

Acute lymphoblastic leukemia (ALL) treatment: This form of cancer is highly curable in children. Treatment falls into three phases: induction therapy, consolidation therapy and maintenance therapy. During the first 5 weeks of treatment called the induction phase, patients initially receive a combination of different chemotherapy drugs. They may go home but need to make frequent visits. Induction is considered the most difficult phase of treatment. KHCC physicians make sure that the child has responded to it by repeating the bone marrow exam before moving on to the next phase of treatment, the consolidation phase, which typically includes four doses of chemotherapy in addition to oral chemotherapy. Then patients start a long phase called the continuation, or maintenance therapy, in which they receive mainly oral chemotherapy and some intravenal drugs. In some cases, some patients may need a bone marrow transplant, but most patients do not need transplants.

Acute myelogenous leukemia (AML) treatment:  The treatment regimen of childhood AML typically includes 2 cycles of induction therapy to induce a remission of the disease. After remission is induced, post-induction treatment is necessary because most patients will have a relapse without additional treatment. In patients without suitable donors for bone marrow transplant from their family, sequential cycles of chemotherapy are administered. Similarly, patients with favorable cytogenetics (chromosomal and genetic factors) can be treated effectively with chemotherapy only. Several studies have demonstrated a clear survival benefit for patients who are treated with allogeneic bone marrow transplants. As a result, patients who have family members that are a match can be treated with marrow transplantation.

Chronic Myelogneous Leukemia (CML) treatment: CML rarely develops in children, but for young patients with CML, bone marrow or stem cell transplants are usually performed in addition to chemotherapy.  The goal of treatment for CML is to eliminate the blood cells containing the abnormal gene. Because it is a "chronic" disease, treatment will not cure the patient, but they may begin to live a relatively normal life.

Chronic Lymphocytic Leukemia (CLL) treatment:  Like CML, CLL rarely affects children. Different types of treatments are used to treat CLL, most commonly chemotherapy, radiation therapy and targeted therapies (when drugs and other substances are used to attack specific cancer cells without affecting normal cells. In some cases, surgery may be needed to remove an enlarged spleen.

Physicians
Pediatric patients receive top quality care from a multidisciplinary team of pediatric oncology specialists that is entirely devoted to diagnosing and treating leukemia and other childhood cancers.

Supportive Care
The pediatric multidisciplinary clinic works in close cooperation with other departments at KHCC so that pediatric patients receive the most comprehensive care possible. Supportive care services at KHCC include: