How Is Leukemia Staged And Classified?

Leukemia is a type of cancer that affects the blood and bone marrow. Unlike other cancers, leukemia doesn’t form solid tumors, so it’s not staged in the traditional way. Instead, doctors classify leukemia based on three key factors:

• Type of blood cell affected: Lymphocytic (affecting lymphocytes) or Myeloid (affecting myeloid cells)
• Rate of progression: Acute (rapid progression) or Chronic (slow progression)
• Genetic mutations: Certain genetic changes can further define leukemia subtypes.

Acute vs. Chronic Leukemia

• Acute Leukemia: Progresses rapidly, leading to a buildup of immature, nonfunctional cells in the bone marrow and blood. Immediate treatment is often required.
• Chronic Leukemia: Progresses slowly, allowing more functional cells to form. It can sometimes be monitored before treatment begins.

Lymphocytic vs. Myeloid Leukemia

• Lymphocytic Leukemia: Affects lymphocytes, a type of white blood cell crucial for the immune system.
• Myeloid Leukemia: Involves myeloid cells, which give rise to red blood cells, platelets, and other types of white blood cells.

Genetic Factors in Leukemia

Certain types of leukemia are classified further by genetic mutations. For instance, Acute Myeloid Leukemia (AML) has several subtypes based on genetic changes, which can influence treatment options.

Types of Leukemia and Subtypes

The four main types of leukemia are:

1. Acute Lymphoblastic Leukemia (ALL)
2. Acute Myeloid Leukemia (AML)
3. Chronic Lymphocytic Leukemia (CLL)
4. Chronic Myeloid Leukemia (CML)

Acute Myeloid Leukemia (AML) Subtypes

AML is classified into eight subtypes (M0–M7) based on the affected cell and its level of maturity. The World Health Organization (WHO) has updated these classifications, determined using the French-American-British (FAB) system, to include genetic and molecular data, offering a more accurate diagnosis.

Phases of Chronic Leukemia

While leukemia is not staged in the traditional way that solid tumor cancer is, chronic leukemias can be described in phases to help guide treatment:

• Chronic Myeloid Leukemia (CML) has three phases:
  • Chronic Phase: Fewer immature cells (blasts), slower disease progression.
  • Accelerated Phase: Increasing blasts, reduced treatment response.
  • Blast Phase: High blast cell count, rapid disease progression, similar to acute leukemia.
• Chronic Lymphocytic Leukemia (CLL): Classified using the Rai or Binet staging systems, which evaluate the number of lymphocytes, involvement of lymph nodes, and organ enlargement (e.g., liver or spleen).

Find a Leukemia Specialist Today

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Further Resources

Looking for trustworthy information on AML or CLL? Join our HealthTree community! We offer up-to-date news, interviews with specialists, and informative webinars for patients and care partners. Connect with others and learn more at:

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• HealthTree for CLL

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