Leukemia : Leukemia is cancer of the blood or bone marrow (which produces blood cells). A person who has leukemia suffers from an abnormal production of blood cells, generally leukocytes (white blood cells). The word Leukemia comes from the Greek leukos which means "white" and aima which means "blood". The DNA of immature blood cells, mainly white cells, becomes damaged in some way. This abnormality causes the blood cells to grow and divide chaotically. Normal blood cells die after a while and are replaced by new cells which are produced in the bone marrow. 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 - and the sufferer becomes ill. Quite simply, the bad cells crowd out the good cells in the blood. Causes Experts say that different leukemias have different causes. The following are either known causes, or strongly suspected causes: ? Artificial ionizing radiation ? Viruses - HTLV-1 (human T-lymphotropic virus) and HIV (human immunodeficiency virus) ? Benzene and some petrochemicals ? Alkylating chemotherapy agents used in previous cancers ? Maternal fetal transmission (rare) ? Hair dyes ? Genetic predisposition - some studies researching family history and looking at twins have indicated that some people have a higher risk of developing leukemia because of a single gene or multiple genes. ? Down syndrome - people with Down syndrome have a significantly higher risk of developing leukemia, compared to people who do not have Down syndrome. Experts say that because of this, people with certain chromosomal abnormalities may have a higher risk. ? Electromagnetic energy - studies indicate there is not enough evidence to show that ELF magnetic (not electric) fields that exist currently might cause leukemia. The IARC (International Agency for Research on Cancer) says that studies which indicate there is a risk tend to be biased and unreliable. Signs and symptoms Common leukemia Signs and symptoms include: • Fever or chills • Persistent fatigue, weakness • Frequent or severe infections • Losing weight without trying • Swollen lymph nodes, enlarged liver or spleen • Easy bleeding or bruising • Recurrent nosebleeds • Tiny red spots in your skin (petechiae) • Excessive sweating, especially at night • Bone pain or tenderness Classification The first type of classification is by how fast the leukemia progresses: • Acute leukemia. In acute leukemia, the abnormal blood cells are immature blood cells (blasts). They can't carry out their normal work, and they multiply rapidly, so the disease worsens quickly. Acute leukemia requires aggressive, timely treatment. • Chronic leukemia. This type of leukemia involves more mature blood cells. These blood cells replicate or accumulate more slowly and can function normally for a period of time. Some forms of chronic leukemia initially produce no early symptoms and can go unnoticed or undiagnosed for years. The second type of classification is by type of white blood cell affected: • Lymphocytic leukemia. This type of leukemia affects the lymphoid cells (lymphocytes), which form lymphoid or lymphatic tissue. Lymphatic tissue makes up your immune system. • Myelogenous (my-uh-LOHJ-uh-nus) leukemia. This type of leukemia affects the myeloid cells. Myeloid cells give rise to red blood cells, white blood cells and platelet-producing cells. Types of leukemia The major types of leukemia are: • Acute lymphocytic leukemia (ALL). This is the most common type of leukemia in young children. ALL can also occur in adults. • Acute myelogenous leukemia (AML). AML is a common type of leukemia. It occurs in children and adults. AML is the most common type of acute leukemia in adults. • Chronic lymphocytic leukemia (CLL). With CLL, the most common chronic adult leukemia, you may feel well for years without needing treatment. • Chronic myelogenous leukemia (CML). This type of leukemia mainly affects adults. A person with CML may have few or no symptoms for months or years before entering a phase in which the leukemia cells grow more quickly. Medications Chemotherapy for leukemia is usually a combination of drugs. This is because different drugs attack leukemia cells in different ways. The combination also helps keep the leukemia cells from becoming resistant to any one drug. Medicine choices For acute leukemia Your treatment plan will include the kind of medicine that works best for the specific type or subtype of leukemia that you have. • Acute lymphoblastic leukemia (ALL) may be treated with chemotherapy medicines (asparaginase, clofarabine, daunorubicin, doxorubicin, methotrexate,nelarabine, or vincristine) and corticosteroids (dexamethasone or prednisone). • Acute myelogenous leukemia (AML) may be treated with chemotherapy medicines (cytarabine, daunorubicin, idarubicin, or mitoxantrone).