Acute Lymphocytic Leukemia
Leukemia is cancer of the white blood cells. White blood cells help your body fight infection. Your blood cells form in your bone marrow. In leukemia, however, the bone marrow produces abnormal white blood cells. These cells crowd out the healthy blood cells, making it hard for blood to do its work. In acute lymphocytic leukemia (ALL), there are too many of specific types of white blood cells called lymphocytes or lymphoblasts. ALL is the most common type of cancer in children. Possible risk factors for ALL include being male, being white, previous chemotherapy treatment, exposure to radiation, and for adults, being older than 70. Symptoms of ALL include: - Weakness or feeling tired - Fever - Easy bruising or bleeding - Bleeding under the skin - Shortness of breath - Weight loss or loss of appetite - Pain in the bones or stomach - Pain or a feeling of fullness below the ribs - Painless lumps in the neck, underarm, stomach, or groin Tests that examine the blood and bone marrow diagnose ALL. Treatments include chemotherapy, radiation therapy, stem cell transplants, and targeted immune therapy. Once the leukemia is in remission, you need additional treatment to make sure that it does not come back.
Introduction
Acute lymphocytic leukemia, or ALL, is cancer of the white blood cells. The increase in the number of these cells leads to overcrowding of healthy blood cells. As a result, the healthy cells are not able to function properly. In ALL, there are too many of specific types of white blood cells called lymphocytes or lymphoblasts. ALL is the most common type of cancer in children. This program explains acute lymphocytic leukemia. It covers its causes, symptoms, diagnosis, and treatment options.
The Blood
Normal blood is made of a fluid called plasma and 3 types of cells:
- White blood cells
- Red blood cells
- Platelets
White blood cells, also called WBCs or leukocytes, help the body fight infections and diseases. Red blood cells, also called RBCs or erythrocytes, carry oxygen from the lungs to the body’s tissues. They also take carbon dioxide from the tissues back to the lungs. The red blood cells give blood its red color. Platelets, also called thrombocytes, help blood to clot when a person is injured. By clotting, bleeding is controlled and the injured person does not lose excessive amounts of blood. Blood cells are formed in the soft, spongy center of bones called the bone marrow. New, undeveloped blood cells are called blasts. Some blasts stay in the marrow to mature, while some travel to other parts of the body to mature.
Acute Lymphocytic Leukemia
Normally, blood cells are produced in a controlled way, as the body needs them. This process helps keep us healthy. When ALL develops, the body produces large numbers of abnormal white blood cells. The ALL cells usually look different from normal white blood cells. They also do not function properly. There are several different types of leukemia. Leukemia is commonly labeled by how quickly it develops and gets worse. In acute leukemia, the disease gets worse quickly. In chronic leukemia, the disease gets worse gradually. Leukemia can also be labeled based on the type of white blood cells it affects. Lymphocytic leukemia affects specific types of white blood cells called lymphocytes or lymphoblasts. Acute lymphocytic leukemia is the most common type of leukemia in young children. It can also affect adults, especially over the age of 70.
Risk Factors
It is usually impossible to specify the cause of ALL in an individual patient. Doctors know factors that can increase the chances of getting ALL. These are known as “risk factors.” Exposure to high-energy radiation is a risk factor for ALL. An example is the atomic radiation seen in survivors of the Hiroshima and Nagasaki bombs. Another risk factor for ALL is long exposure to chemicals, such as benzene. Past treatment with chemotherapy or radiation therapy increases a person’s risk for ALL. Certain genetic conditions, such as Down syndrome, are also a risk factor for ALL. Other risk factors for adults include:
- Being male
- Being white
- Being older than 70
Other risk factors for children include:
- Having a brother or sister with leukemia
- Being white or Hispanic
- Being exposed to x-rays before birth
Not everybody who has risk factors for acute lymphocytic leukemia develops it. Some people who have no risk factors for ALL will still develop it.
Symptoms
Leukemia cells are abnormal cells that cannot do what normal white blood cells do. They cannot help the body fight infections. For this reason, people with leukemia often get infections and have fevers. As leukemia cells increase in number, the healthy red blood cells and platelets decrease due to overcrowding. As a result, the body does not receive enough oxygen. Without enough red blood cells, a person develops a condition called anemia. Anemia causes a person to look pale and feel weak and tired. Without enough platelets, patients bleed and bruise easily. Some of the common symptoms of ALL include:
- Fever or chills
- Weakness and fatigue
- Frequent infections
- Unintended weight loss
- Swollen or tender lymph nodes
- Easy bruising or bleeding
Other symptoms of ALL include:
- Tiny red spots under the skin, called petechiae, caused by abnormal bleeding
- Swollen or bleeding gums
- Sweating, especially at night
- Bone or joint pain
- Painless lumps in the neck, underarm, stomach, or groin
Like all blood cells, leukemia cells travel through the body. Depending on where these cells accumulate, patients with leukemia may have a number of symptoms. In acute leukemia, symptoms appear and get worse quickly. People with acute leukemia go to their doctor because they feel sick. These symptoms may not be caused by ALL or another type of leukemia. Make sure to see a doctor to find out what is causing your symptoms.
Diagnosis
Your healthcare provider will ask about your family medical history in addition to your own. A physical exam will be performed. Blood tests also help in diagnosing leukemia but do not diagnose the type. Your healthcare provider may test bone marrow samples to find out more. ALL always arises from changes that happen in the chromosomes. For example, sometimes in ALL part of one chromosome is moved to another chromosome. This is called the Philadelphia chromosome. Special blood or bone marrow tests may be done to look for these changes in the chromosomes. Further testing may be done to diagnose one type of leukemia from another. Ask your healthcare provider about additional testing you may need. A certain type of dye will cause a specific type of leukemia cell to change color, but not other types of leukemia cells. This helps determine which type of white blood cells are affected by the cancer.
Staging
The extent or spread of cancer is usually described as stages. There is no standard staging system for ALL. ALL is described according to:
- Which subtype of ALL a person has
- Whether the leukemia has spread outside the blood and bone marrow
This information is used instead of the stage to plan treatment. For adults, the disease is also described as untreated, in remission, or recurrent. Untreated ALL is newly diagnosed and has not yet been treated. ALL in remission has been successfully treated and the patient does not have any symptoms. Recurrent ALL is cancer that has come back after being in remission. For children, ALL is also described in the following groups:
- Standard, or low, risk
- High risk
Children in the high risk group often receive more aggressive treatment than children with standard risk ALL. The standard, or low, risk group includes children between one to ten years of age. These children also have a white blood cell count of less than 50,000/ µL at diagnosis.
The high risk group includes children younger than one year of age and children ten years or older. These children also have a white blood cell count of 50,000/ µL or higher at diagnosis. Acute lymphocytic leukemia can spread to other parts of the body through blood vessels and lymph channels. If leukemia cells are found, more tests are needed to determine the extent of the disease. A spinal tap checks for leukemia cells in the fluid around the brain and spinal cord. It is done by inserting a needle into the spinal column. Another name for a spinal tap is a lumbar puncture. Chest x-rays can reveal signs of leukemia in the chest. Other imaging tests, such as a CT scan or an MRI, may also be done to look for evidence of cancer.
Treatment and Supportive Care
Treatment for leukemia is complex. It is not the same for all patients. Treatment for acute lymphocytic leukemia depends on:
- The extent of the disease
- Whether the leukemia has been treated before
- The patient’s age, symptoms, and general health
The goals of treatment for ALL are to:
- Stop the disease, also called remission
- Prevent it from coming back, which is called relapsing
Many people with ALL can be cured. Treatment for ALL may involve chemotherapy, radiation therapy, stem cell transplant, or targeted therapy. Often some combination of these treatments is used. Chemotherapy is the use of drugs to kill cancer cells. Chemotherapy is usually given in the blood stream through an IV. Sometimes it may be taken by mouth. Radiation therapy uses high-energy rays to kill cancer cells and stop them from growing and spreading. The radiation that treats the cells comes from a machine. To treat ALL, the radiation may be aimed at a specific area of the body where there is a collection of leukemia cells. Other patients may receive radiation that is directed at the body as a whole. This type of radiation therapy is called total-body irradiation. It is usually given before a stem cell transplant. Stem cell transplants are another treatment option for ALL. First the patient’s leukemia-producing bone marrow is destroyed by high doses of drugs and radiation. It is then replaced by healthy bone marrow. Stem cells are removed from the blood or bone marrow of a donor. When the cells are taken from the bone marrow, the procedure is sometimes called a bone marrow transplant. The donor’s stem cells are given to the patient. These stem cells grow into and restore the patient’s blood cells. Targeted therapy is another treatment for ALL. It uses drugs or other substances to identify and attack specific cancer cells without harming normal cells. Certain drugs may also be used to block an enzyme that causes the body to make more white blood cells than it needs. There may also be clinical trials available for people with ALL. Clinical trials test new medical approaches and treatments. ALL and its treatment can lead to other health problems. It is important to have supportive care before, during, and after cancer treatment. Supportive care is treatment to control symptoms, to relieve the side effects of therapy, and to help you cope with emotions. Supportive care also deals with the pain associated with cancer and its treatments. Your healthcare provider or a pain control specialist can suggest ways to relieve or reduce pain.
Summary
Acute lymphocytic leukemia, or ALL, is cancer of the white blood cells. The increased growth of these cells leads to overcrowding of healthy blood cells. As a result, the healthy cells are not able to function properly. In ALL, there are too many of specific types of white blood cells called lymphocytes or lymphoblasts. ALL is the most common type of cancer in children. Treatment options for ALL include chemotherapy, radiation therapy, stem cell transplant, or targeted therapy. Often some combination of these treatments is used. Most people with ALL can be cured. Research already has led to advances that have helped people live longer. Research continues to find better ways to care for people with ALL.
