Stanford University School of Medicine defines leukemia as a "cancer of the blood cells--usually the white blood cells." It strikes adults and children of both sexes.
Thanks to the development of treatment protocols such as bone marrow transplant and multi-drug combinations, survival rates have skyrocketed since 1970. Leukemia is no longer the automatic death sentence that it once was.
Definition
The National Cancer Institute defines leukemia as a cancer "that starts in blood-forming tissue such as the bone marrow and causes large numbers of blood cells to be produced and enter the bloodstream." It generally occurs when white blood cells start reproducing uncontrollably. In addition to being dysfunctional, these immature white cells also crowd out other cells.
In many instances, the overgrown cells are are called blasts. When a patient has an elevated number of blasts, the condition is described as being a blast crisis.
Types
Since there are many types of white blood cells, there are also many types of leukemia. Broadly, leukemias are classified by the particular type of cell that grows uncontrollably, whether this growth is chronic or acute and whether it strikes children or adults. The distinction between adult and childhood variants is not always made.
Some of the more common types of leukemia are adult acute lymphoblastic leukemia, childhood acute lymphoblastic leukemia, adult acute myeloid leukemia, childhood acute myeloid leukemia, chronic lymphocytic leukemia and chronic myelogenous leukemia.
Risks
The National Cancer Institute reports that 1.3 percent of people born in 2010 will be diagnosed with leukemia. This means that 1 in 77 people born in 2010 will get leukemia.
Risks for getting leukemia include radiation exposure, smoking, exposure to benzene, a family history of leukemia and chemotherapy with alkylating agents or topoisomerase inhibitors.
Prognosis and Mortality
The National Cancer Institute explains that the five-year survival rate for all types of leukemia between 1999 and 2006 was 54.1 percent. The survival rate for children with acute lymphoblastic leukemia was 85 to 90 percent.
For all patients between 2003 and 2007, the median age at death was 74.
Treatment
Treatment of leukemia depends upon whether it is acute or chronic. If the leukemia is acute, the patient is treated immediately. Very strong chemotherapeutic drugs are given--often in combination--to induce a remission. After remission, additional drugs are needed to maintain the remission. In many instances, a complete cure is possible.
Treatment may not be needed immediately if the patient has a chronic variant. The doctor may opt to wait until symptoms get worse before treating. While chronic leukemias are not curable, drugs such as Imatinib may keep the disease in check.
Treatment for either acute or chronic leukemia may also include a bone marrow transplant, also referred to as a stem cell transplant. Very high doses of chemo are used to kill off all the blood-forming cells in the patient's bone marrow. New marrow from a donor--or in some instances from the patient themselves--is used to repopulate the cells.
