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Acute Lymphoblastic Leukemia (ALL)

What is Acute Lymphocytic Leukemia (ALL)?


Acute (sudden onset) lymphocytic leukemia (ALL) is also known as lymphoblastic or lymphoid leukemia. It is the most common form 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 lymphocytes. These lymphocyte cancer cells, also called blasts, are not normal. They 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 leukemia can occur over a short period of days to weeks. Symptoms are similar to those of other leukemias.


ALL accounts for about 75 to 80 percent of the childhood leukemias.


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 will look at several things to tell which risk group your child is in. One is the child’s age. Another is how many white blood cells are found in a sample of your child’s blood.

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 will also take into account:

  • Which type of B or T lymphocyte formed the leukemia cells. There are different kinds of lymphocytes. It is important to know which kind started the cancer.
  • The type of changes found in the cancer cell genes
  • How quickly the leukemia responds to therapy
  • Whether the cancer has spread to the brain and spinal cord, testicles, or certain other parts of the body

Typical Treatment

The specialists at Cincinnati Children’s look at each patient’s needs and then they recommend the treatment that suits their status best. Treatment is usually started right away and often includes these phases:

Induction Phase

Treatment begins with a month of intense chemotherapy. A lot of it will occur in the hospital. Strong medicine is given through a vein. Treatments will likely also include medicine given through a spinal tap. This step is to kill any cancer cells in the brain or spinal cord. Radiation is sometimes used as well. This intense phase causes remission, in which the disease appears to be gone, in around 95 percent of patients.

Consolidation / Intensification Phase

Over the next month or two, more chemotherapy drugs are usually given. The goal is to get rid of any leukemia cells that may still be hidden. Some children may get a blood bone marrow transplant. Others may benefit from immune-based therapy. In this type of therapy, special antibodies are given to help the body’s immune system target the cancer cells.

Maintenance Phase

In this phase, chemotherapy is continued. Intense treatment periods are often alternated with less intense periods. If the leukemia stays in remission, the total treatment time is usually two to three 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 often have certain health problems later in life. We offer a special program to help these patients through adulthood. For more information, see our Cancer Survivorship Program.


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.

It’s important to remember that statistics are not based on large pools of data. Every child is different. Your doctor will talk with you about your child’s outlook and will recommend the best course of treatment.

Last Updated 08/2021

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