Leukemia is cancer of the bodys blood-forming tissues, including the bone marrow and the lymphatic system. It is caused by genetic changes in blood cells produced in bone marrow cells, but all known leukemia-causing genetic mutations are acquired during life, not inherited. Scientists have yet to determine what causes the genetic changes in bone marrow cells that lead to leukemia. However, certain risk factors are associated with the disease, including:
- Age: Risk of leukemia increases with age, and the disease is most common in people over 60 years old.
- Sex: All leukemias are more common in those assigned male at birth than those assigned female.
- Smoking: The only proven lifestyle-related risk factor for acute leukemias is smoking.
- Benzene exposure: Exposure to benzene, a chemical used in some manufacturing processes, is a known risk factor for acute myeloid leukemia.
In general, leukemia is thought to occur when some blood cells acquire changes (mutations) in their genetic material or DNA. Normally, the DNA tells the cell to grow at a set rate and to die at a set time. But in leukemia, the mutations tell the blood cells to continue growing and dividing, and blood cell production becomes out of control. Over time, these abnormal white blood cells can outnumber the healthy white blood cells, red blood cells, and platelets within the body, rendering the blood less effective at doing its job.
