Chronic leukemia can progress slowly and with few symptoms. Causes of most cases are unknown. Persons with Down syndrome and certain other genetic abnormalities have higher than normal incidence of leukemia. It has also been linked to excessive exposure to ionizing radiation and to certain chemicals such as benzene, a commercially used toxic liquid that is also present in lead-free gasoline. When a physician does suspect leukemia, diagnosis can be made using blood tests and biopsy of the bone marrow.
Chemotherapy is the most effective method of treating leukemia.
Various anticancer drugs are used, either in combination or as single agents. Transfusions of blood components and antibiotics are used as supportive treatments. To prevent persistence of hidden cells, therapy of the central nervous system has become standard treatment, especially in acute lymphocytic leukemia. Under appropriate conditions, bone marrow transplantation may be useful in the treatment of certain leukemias. Very little is known about what causes the disease or how to prevent it.