The word leukemia comes from the Greek word leukos which mean “white” and aima which means “blood”. Leukemia is cancer of the blood and/or bone marrow (which produces blood cells) characterized by uncontrollable proliferation of blood cells, usually white blood cells (leukocytes). Leukemia is a broad term covering a spectrum of diseases.

Although leukemia can attack any form of blood component (including plasma, white blood cells, red blood cells, and platelets), most forms of leukemia affect the white blood cells. The DNA of immature blood cells, mainly white blood cells, becomes damaged in some manner. This abnormality causes the blood cells to grow and divide chaotically. Normal blood cells die after a while new blood cells are produced in the bone marrow; once they’re produced, new cells (called blast) may remain in the marrow to mature, or may travel to other parts of the body.

Normally, blood cells are produced in an orderly, controlled and as the body needs them. In contrast, when leukemia develops the body produces large number of abnormal blood cells. The abnormal blood cells do not die so easily, and accumulate, occupying more and more space. As more and more space is occupied by these faulty blood cells there is less and less space for the normal cells – thus the sufferer becomes ill. Quite simply, leukemia cells crowd out healthy white blood cells, red blood cells, or platelets in the blood.

Leukemia makes up about 5% of all cancer cases in the United States and the most common childhood cancer. More than half of all cases of leukemia occur in people over the age of 60, and men are affected about 30% more often than women; it occurs slightly more often in whites than blacks.

There are 4 different categories of leukemia (Acute Lymphocytic Leukemia – ALL, Chronic Lymphocytic Leukemia – CLL, Acute Myelogenous Leukemia – AML, and Chronic Myelogenous Leukemia – CML) based on how quickly the disease develops and worsens, and by the type of blood cell that is affected.