What is Acute Lymphocytic Leukemia (ALL)?
Overview
Acute (sudden onset) lymphocytic leukemia (ALL) is also known as lymphoblastic or lymphoid leukemia. It is the most common type of leukemia in children.
Lymphocytes are a type of white blood cell that help fight infection. They are formed in the center cavity of certain bones, in a sponge-like tissue called marrow.
In this form of leukemia, the bone marrow makes too many abnormal lymphocytes. These abnormal lymphocyte cancer cells are called lymphoblasts. Lymphoblasts do not fight infection well. They also crowd out other kinds of blood cells forming in the bone marrow, causing shortages. Because of this, there may not be enough oxygen-carrying red blood cells. There may also not be enough platelets, which help blood clot when needed.
Acute Lymphocytic Leukemia usually shows signs and symptoms over a period of days to weeks. Signs and symptoms are similar to those of other leukemias: fatigue, fevers, bone pain, persistent infections, pale skin color, abdominal pain, loss of appetite, and excessive bruising or frequent nosebleeds.
Incidence
ALL accounts for about 75 to 80 percent of the childhood leukemias.
Causes
Most ALL cancer cells contain abnormal genes. What has caused the cells’ genetic code to be altered is often not known.
Risk Groups
Many types of cancer are grouped in Stages based on how far the cancer has spread when found. Because ALL is in the blood, it has already spread throughout the body at the time of diagnosis. So, instead of Stages, specialists put leukemia patients in "risk groups."
Risk groups help the team decide on the best course of treatment. Children with high-risk ALL usually receive stronger treatments than children with standard risk ALL. Your doctor (oncologist) will look at several things to tell which risk group your child is in. One is the child’s age at diagnosis. Another is how many white blood cells are found in a sample of your child’s blood at diagnosis.
Often, patients are grouped as follows:
Standard (low) risk: Children aged 1 to 9 years who have a white blood cell count under 50,000.
High risk: Children younger than 1 year or older than 9 years, and any child with a white blood cell count of 50,000 or more.
However, your doctor (oncologist) will also consider:
- Whether B or T lymphocytes formed the leukemia cells. There are various kinds of lymphocytes, and it is important to know which kind started the cancer.
- The type of changes found in the cancer cell genes
- Whether the cancer has spread to the brain and spinal cord, testicles, or certain other parts of the body
- How quickly the leukemia responds to therapy
Typical Treatment
The oncologists at Cincinnati Children’s look at the characteristics of each patient’s leukemia and then recommend the treatment that is best for each patient. Treatment is usually started right away and often includes these phases:
Induction Phase
Treatment begins with one month of intense chemotherapy. All or nearly all of this therapy will be given in the hospital. Strong medicine is given through a vein and by mouth. Treatments will also include medicine given in the spine through a spinal tap. This step is to kill any cancer cells in the brain or spinal cord. The Induction phase causes remission in about 95% of patients. Remission means the leukemia is no longer detectable by testing. However, we know that leukemia cells are still present in the body.
Consolidation/Interim Maintenance/Intensification Phases
Over the next seven to eight months, more anti-leukemia medications are given. Some medications are given in the hospital, and some are given in the outpatient clinic. The goal is to get rid of any leukemia cells that may still be hidden.
Some children will best benefit from just additional chemotherapy while other children will best benefit from additional chemotherapy plus immune-based therapy. In this type of therapy, special antibodies are given to help the body’s immune system target the cancer cells. Treatment is individualized to each child’s type of leukemia.
Maintenance Phase
In this phase, chemotherapy is continued, but is given in the outpatient clinic. Also, during maintenance, the child is required to take chemotherapy by mouth at home. Maintenance usually lasts about one and a half years. Overall time for leukemia treatment from start to finish is about two and a half years
Relapsed and Refractory Acute Lymphoblastic Leukemia
Sometimes leukemia doesn’t go away in the first few months of treatment. This is called refractory” ALL. Leukemia may come back after a time of remission. This is called “relapsed” ALL. If either of these happens, a new treatment plan may include:
- A more intense and/or longer course of chemotherapy
- Different chemotherapy medicines
- A stem cell transplant
- Immunotherapy
Immunotherapy is a huge breakthrough in the treatment of refractory and relapsed ALL. Immunotherapy uses the body’s immune system to help find and kill cancer cells. One example is chimeric antigen receptor (CAR T-cell) therapy. CAR T-cell therapy changes a type of immune cell called T cells to find and attack the cancer hiding in the body. It may provide long-term remission. It may be a cure for patients with B-ALL.
Immunotherapies can be used alone or in combination with other cancer treatments. Only a small number of children’s hospitals, including Cincinnati Children’s, offer immunotherapy for ALL.
Lifelong Follow Up
Survivors of childhood cancer may have chemotherapy-related health problems later in life. We offer a special program to help these patients through adulthood. For more information, see our Cancer Survivorship Program.
Outlook
The outlook for most children with ALL is good and has improved a lot over the past twenty years. According to the National Cancer Institute, over 95 percent of children treated for ALL go into remission. With today's treatment, in about 80 percent of these cases, the cancer should not return. Your oncologist will talk with you about your child’s outlook and will recommend the best course of treatment.
