Leukemia is cancer of bone marrow stem cells – immature cells that normally would develop into either red blood cells, white blood cells or platelets.
When someone has leukemia, the bone marrow produces abnormal blood cells that do not die when they become old, as normal, healthy cells do. These abnormal cells build up in the bone marrow and prevent normal blood cells from developing. Almost all leukemia begins in the bone marrow, and it usually spreads to the blood. Leukemia may also be found in other tissues, such as lymph nodes and the spleen.
Diagnosing leukemia in its earliest stages can improve a patient’s prognosis, so it is important to be tested as soon as possible if leukemia is suspected.