Leukemia

What is Leukemia? 

Leukemia is a type of blood cancer affecting the white blood cells. It typically results from abnormal production of the white blood cells in the bone marrow.  

The bone marrow is the spongy tissue, nestled within the flat bones, and it is responsible for the hematopoiesis (Production of all blood cells).

There are two major subtypes of leukemia: acute, where the abnormal production occurs at an earlier stage of blood cell formation and takes a more aggressive form, and chronic, where the abnormal proliferation takes place at a more mature phase of cell production and often has a more indolent presentation.  

Leukemia is then divided depending on the cell lineage affected by either myeloid or lymphoid.

Below are the 4 main categories of leukemia:

  • Acute Lymphocytic Leukemia (ALL) is a rapid-growing leukemia that affects lymphoid cells (a type of immune cell produced in the bone marrow and is found in the blood and lymph tissue). It’s more common in children but can also occur in adults.  
  • Acute Myeloid Leukemia (AML) is a rapid-growing leukemia that affects myeloid cells (blood-forming cells found in the bone marrow). More adults are diagnosed with AML than children, but it can also occur in children, though that is rare.
  • Chronic Lymphocytic Leukemia (CLL) is a slow-growing leukemia that affects lymphoid cells. It impacts adults, particularly those over 55 years old, and is rarely diagnosed in children.
  • Chronic Myeloid Leukemia (CML) is a slow-growing leukemia that affects myeloid cells. It is uncommon in children and most commonly impacts older adults.

Other less common types of leukemia include:

  • Hairy Cell Leukemia is a rare, slow-growing leukemia in which the cells appear "hairy" under a microscope. It occurs mostly in middle-aged men.
  • T-cell Prolymphocytic Leukemia (T-PLL) is a rare form of leukemia that affects mature T-cells. While it can be initially slow-growing, T-Pull quickly progresses to an advanced and aggressive disease. It is most common in older adults.
  • Large Granular Lymphocytic Leukemia (LGL) is a rare chronic leukemia that develops from mature T cells or natural killer (NK) cells. NK cells are the body’s first immune response defense against infection and disease. In LGL, the NK cells contain small particles or granules and reproduce rapidly, crowding out healthy cells.
  • Juvenile Myelomonocytic Leukemia (JMML) is a rare leukemia that occurs in young children, usually under the age of 4. JMML cells can gather in other organs, such as the spleen and lungs.

Risk Factors

While the exact cause of leukemia is not known, several risk factors have been identified that can increase the likelihood of developing the disease. These risk factors can be categorized into genetic, environmental, and lifestyle-related factors, including:

  • Genetic Risk Factors
    • Family History: Having a close relative with leukemia can increase the risk.
    • Genetic Disorders: Certain genetic disorders, such as Down syndrome, Li-Fraumeni syndrome, and Fanconi anemia, are associated with a higher risk of leukemia.
    • Inherited Syndromes: Inherited conditions like neurofibromatosis and Bloom syndrome also raise leukemia risk.
  • Environmental and Occupational Risk Factors
    • Radiation Exposure: High levels of radiation exposure, such as from an atomic bomb blast, nuclear reactor accident, or radiation therapy for other cancers, can increase the risk.
    • Chemical Exposure: Long-term exposure to certain chemicals, such as benzene (found in gasoline and used in the chemical industry), is linked to a higher risk of leukemia.
  • Lifestyle and Other Risk Factors
    • Smoking: Smoking cigarettes is associated with an increased risk of acute myeloid leukemia (AML).
    • Age: The risk of most types of leukemia increases with age, although some types, like acute lymphocytic leukemia (ALL), are more common in children.
    • Gender: Males are generally at a higher risk of developing leukemia compared to females.
  • Medical and Biological Factors
    • Immune System Suppression: Long-term use of immune-suppressing drugs can increase the risk.
    • Infections: Certain viral infections, such as the human T-cell leukemia virus-1 (HTLV-1), are linked to an increased risk of adult T-cell
    • Certain Blood Disorders: Conditions like myelodysplastic syndromes and polycythemia vera can increase the risk of leukemia.
  • Other Factors
    • Exposure to Electromagnetic Fields: Some studies suggest a possible link between exposure to electromagnetic fields and a slight increase in leukemia risk, though the evidence is not conclusive.
    • Chemotherapy and Radiation Therapy: Previous treatment with chemotherapy or radiation therapy for other cancers can increase the risk of developing secondary leukemia.

Choosing the cancer center that’s right for you is one of the most important decisions you make in your cancer journey. At GW Cancer Center, you’ll be treated by one of the region’s most highly-rated leukemia teams.