Leukemia

Leukemia

Leukemia or leukaemia (Greek leukos О»ÐžµÐŸ...ОÑ"ПЊП‚, "white"; aima О±ÐžÐ‡ÐžÑ˜Ðž±, "blood") is a cancer of the blood or bone marrow and is characterized by an abnormal proliferation (production by multiplication) of blood cells, usually white blood cells (leukocytes). It is part of the broad group of diseases called hematological neoplasms.

Contents

* 1 Symptoms

* 2 Four major types

* 3 Causes and risk factors

* 4 Treatment options for leukemia by type

o 4.1 Acute Myelogenous Leukemia (AML)

+ 4.1.1 Initial treatment of AML

+ 4.1.2 Follow-up treatment

+ 4.1.3 Consolidation or maintenance therapy

o 4.2 Chronic Myelogenous Leukemia (CML)

o 4.3 Acute Lymphocytic Leukemia (ALL)

o 4.4 Chronic Lymphocytic Leukemia (CLL)

+ 4.4.1 Transformation of CLL to high-grade disease or aggressive non-Hodgkin's lymphoma

+ 4.4.2 Chemotherapy for CLL

o 4.5 Hairy Cell Leukemia (HCL)

* 5 Research

* 6 Incidence

* 7 External links

Symptoms

Damage to the bone marrow, by way of displacing the normal bone marrow cells with higher numbers of immature white blood cells, results in a lack of blood platelets, which are important in the blood clotting process. This means people with leukemia may become bruised, bleed excessively, or develop pinprick bleeds (petechiae).

White blood cells, which are involved in fighting pathogens, may be suppressed or dysfunctional. This could cause the patient's immune system to be unable to fight off a simple infection or to start attacking other body cells.

Finally, the red blood cell deficiency leads to anemia, which may cause dyspnea. All symptoms can be attributed to other diseases; for diagnosis, blood tests and a bone marrow examination are required.

Some other related symptoms:

* Fever, chills, night sweats and other flu-like symptoms

* Weakness and fatigue

* Swollen or bleeding gums

* Neurological symptoms (headache)

* Enlarged liver and spleen

* Frequent infection

* Bone pain

* Joint pain

* Dizziness

* Swollen tonsils

The word leukemia, which means 'white blood', is derived from the disease's namesake high white blood cell counts that most leukemia patients have before treatment. The high number of white blood cells are apparent when a blood sample is viewed under a microscope. Frequently, these extra white blood cells are immature or dysfunctional. The excessive number of cells can also interfere with the level of other cells, causing a harmful imbalance in the blood count. Leukemia was also caused largely in Japan due to the atom bomb dropped in World War 2.

Some leukemia patients do not have high white blood cell counts visible during a regular blood count. This less-common condition is called aleukemia. The bone marrow still contains cancerous white blood cells which disrupt the normal production of blood cells. However, the leukemic cells are staying in the marrow instead of entering the bloodstream, where they would be visible in a blood test. For an aleukemic patient, the white blood cell counts in the bloodstream can be normal or low. Aleukemia can occur in any of the four major types of leukemia, and is particularly common in hairy cell leukemia.

[edit] Four major types

Leukemia is a broad term covering a spectrum of diseases.

Leukemia is clinically and pathologically split into its acute and chronic forms.

* Acute leukemia is characterized by the rapid proliferation of immature blood cells. This crowding makes the bone marrow unable to produce healthy blood cells. Acute forms of leukemia can occur in children and young adults. (In fact, it is a more common cause of death for children in the US than any other type of malignant disease). Immediate treatment is required in acute leukemias due to the rapid progression and accumulation of the malignant cells, which then spill over into the bloodstream and spread to other organs of the body. Central nervous system (CNS) involvement is uncommon, although the disease can occasionally cause cranial nerve palsies.

* Chronic leukemia is distinguished by the excessive build up of relatively mature, but still abnormal, blood cells. Typically taking months to years to progress, the cells are produced at a much higher rate than normal cells, resulting in many abnormal white blood cells in the blood. Chronic leukemia mostly occurs in older people, but can theoretically occur in any age group. Whereas acute leukemia must be treated immediately, chronic forms are sometimes monitored for some time before treatment to ensure maximum effectiveness of therapy.

Furthermore, the diseases are classified into lymphocytic or lymphoblastic which indicate that the cancerous change took place in a type of marrow cell that normally goes on to form lymphocytes, and myelogenous or myeloid which indicate that the cancerous change took place in a type of marrow cell that normally goes on to form red cells, some types of white cells, and platelets (see lymphoid cells vs. myeloid cells).

Combining these two classifications provides a total of four main categories:

Acute Chronic

lymphocytic leukemia Acute lymphocytic leukemia (also known as Acute Lymphoblastic Leukemia, or ALL) is the most common