Doctors determine the stage of leukemia by evaluating factors such as the number of leukemia cells in the blood and bone marrow, the spread of leukemia to other parts of the body, and the person’s overall health.

Doctors usually categorize leukemia into four main types based on the type of blood cells it affects:

Staging is the process of determining the extent or severity of a disease.

This article covers the stages of leukemia based on its type. It also discusses how staging works, the treatment options available, and a person’s potential outlook.

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Doctors stage leukemia based on factors such as:

  • the type of leukemia
  • the number and type of cells the cancer affects
  • the presence or absence of cancerous cells in various parts of the body
  • the results of imaging tests and bone marrow biopsies

Healthcare professionals use the following tests to stage leukemia:

  • Blood tests: Complete blood count (CBC), blood chemistry tests, and blood protein tests determine the number of white blood cells, red blood cells, and platelets in the blood. They can also identify any abnormal cells.
  • Bone marrow biopsy: Doctors take a sample of bone marrow from the hip bone to assess the presence of leukemia cells in the bone marrow.
  • Imaging tests: X-rays, CT scans, MRI scans, and PET scans can help doctors determine the extent of the cancer in the body and identify any tumors or masses.
  • Lumbar puncture (spinal tap): Doctors take a sample of cerebrospinal fluid from the spinal canal to determine whether leukemia cells have spread to the central nervous system.

Based on the results of these tests, doctors will determine the stage of the leukemia and create a treatment plan tailored to an individual’s needs.

It is important to remember that the stage of leukemia can change over time and that doctors will reevaluate it periodically during treatment.

There is no standard staging system for ALL. Instead, doctors describe the disease as untreated, in remission, or recurrent:

  • Untreated: This is newly diagnosed ALL. A person has not yet received treatment but has signs or symptoms of leukemia.
  • In remission: When ALL is in remission, healthcare professionals have successfully treated it. A person’s CBC is normal at this stage, and 5% or fewer bone marrow cells are blasts, or immature blood cells.
  • Recurrent: The leukemia has come back after remission.

The National Cancer Institute notes that, as with ALL, there is no standard staging system for AML. Doctors describe ALL as untreated, in remission, refractory, or recurrent:

  • Untreated: In this stage, a person has not yet received treatment for the leukemia. A person’s CBC is abnormal, and at least 20% of the bone marrow cells are blasts. A person also has signs and symptoms of leukemia.
  • In remission: Fewer than 5% of the bone marrow cells are blasts. There are no signs or symptoms of leukemia.
  • Refractory: If a person does not go into remission after treatment, doctors describe their condition as refractory cancer.
  • Recurrent: The leukemia has come back after remission.

The stages of CLL are as follows:

  • Stage 0: In this early stage, a person has an elevated number of lymphocytes in their blood but no other signs or symptoms. This type of leukemia progresses slowly. Doctors also refer to it as indolent CLL.
  • Stage I: A person has an elevated number of lymphocytes, and the lymph nodes are larger than usual.
  • Stage II: In addition to the elevated lymphocytes and larger lymph nodes, the liver or spleen is larger than usual.
  • Stage III: A person has elevated lymphocytes and lower-than-usual levels of red blood cells.
  • Stage IV: This stage involves an excessive number of lymphocytes in the blood and a decreased amount of platelets. A person may have enlarged lymph nodes, liver, or spleen and a low red blood cell count.

According to the American Cancer Society, CML has three phases:

  • Chronic phase: In this early stage, a person has increased number of blasts in the blood and bone marrow. Fewer than 10% of the cells are blasts.
  • Accelerated phase: The leukemia is growing more quickly and may be causing symptoms such as fever, weight loss, and anemia. In this phase, any of the following can be true:
    • At least 15% but fewer than 30% of the cells are blasts.
    • The blood is made up of 20% or more basophils.
    • At least 30% of the blood consists of blasts and promyelocytes.
    • A person has very low platelet counts that are not a result of the treatment.
    • Leukemia cells that have the Philadelphia chromosome have new chromosomal changes.
  • Blast, or acute, phase: In this phase, 20% or more of the cells in the blood and bone marrow are blasts.

In the early stages of leukemia, doctors may use a watchful waiting approach. This mean they will observe a person’s condition and begin treatment only if symptoms or signs of progression develop.

Other treatment options include:

Doctors will determine which treatment option is best suited for each individual, depending on the type of leukemia and the stage.

The outlook for a person with leukemia depends on factors such as the type of leukemia, the stage of the disease, and the person’s overall health.

If a person receives a diagnosis and treatment when leukemia is in the earlier stages, they have a greater chance of a favorable outcome.

According to the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) program, the overall 5-year survival rate for people with leukemia is almost 66%.

The 5-year relative survival rates for the different types of leukemia are as follows:

Each type of leukemia has its own staging system.

The stage of a person’s leukemia will determine the treatment options and outlook. It is important for a person to work with their healthcare team to understand the implications for their specific case.