Leukemia (American English American English is a set of dialects of the English language used mostly in the United States. Approximately two thirds of native speakers of English live in the United States) or leukaemia (Standard English Standard English is a form of the English language that is accepted as a national norm. It encompasses grammar, vocabulary, and spelling. In Britain, it is often associated with the RP accent, and in the United States with the General American accent but in fact can be spoken with any pronunciation; Greek leukos λευκός, "white"; aima αίμα, "blood") is a cancer Cancer /ˈkænsər/ (medical term: malignant neoplasm) is a class of diseases in which a group of cells display uncontrolled growth (division beyond the normal limits), invasion (intrusion on and destruction of adjacent tissues), and sometimes metastasis (spread to other locations in the body via lymph or blood). These three malignant properties of the blood Blood is a specialized bodily fluid that delivers necessary substances to the body's cells – such as nutrients and oxygen – and transports waste products away from those same cells or bone marrow Bone marrow is the flexible tissue found in the hollow interior of bones. In adults, marrow in large bones produces new blood cells. It constitutes 4% of total body weight, i.e. approximately 2.6 kg in adults characterized by an abnormal increase of blood cells The cell is the functional basic unit of life. It was discovered by Robert Hooke and is the functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. Some organisms, such as most bacteria, are unicellular . Other organisms, such as humans,, usually leukocytes (white blood cells White blood cells , or leukocytes (also spelled "leucocytes"), are cells of the immune system defending the body against both infectious disease and foreign materials. Five different and diverse types of leukocytes exist, but they are all produced and derived from a multipotent cell in the bone marrow known as a hematopoietic stem cell). Leukemia is a broad term covering a spectrum of diseases. In turn, it is part of the even broader group of diseases called hematological neoplasms Hematological malignancies are the types of cancer that affect blood, bone marrow, and lymph nodes. As the three are intimately connected through the immune system, a disease affecting one of the three will often affect the others as well: although lymphoma is technically a disease of the lymph nodes, it often spreads to the bone marrow, affecting.

In 2000, approximately 256,000 children and adults around the world developed some form of leukemia, and 209,000 died from it.^[1] About 90% of all leukemias are diagnosed in adults.^[2]

Classification

Leukemia is clinically and pathologically subdivided into a variety of large groups. The first division is between its acute This adjective is part of the definition of several diseases and is, therefore, incorporated in their name, for instance, severe acute respiratory syndrome, acute leukemia and chronic In medicine, a chronic disease is a disease that is long-lasting or recurrent. The term chronic describes the course of the disease, or its rate of onset and development. A chronic course is distinguished from a recurrent course; recurrent diseases relapse repeatedly, with periods of remission in between. As an adjective, chronic can refer to a forms:

• Acute leukemia is characterized by the rapid increase of immature blood cells. This crowding makes the bone marrow unable to produce healthy blood cells. Immediate treatment is required in acute leukemia 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. Acute forms of leukemia are the most common forms of leukemia in children.
• Chronic leukemia is distinguished by the excessive build up of relatively mature, but still abnormal, white blood cells. Typically taking months or 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. Whereas acute leukemia must be treated immediately, chronic forms are sometimes monitored for some time before treatment to ensure maximum effectiveness of therapy. Chronic leukemia mostly occurs in older people, but can theoretically occur in any age group.

Additionally, the diseases are subdivided according to which kind of blood cell is affected. This split divides leukemias into lymphoblastic or lymphocytic leukemias Lymphoid leukemia is a type of leukemia affecting circulating cells of lymphoid origin. This is in contrast to lymphoma, which is a solid tumor of lymphoid cells and myeloid or myelogenous leukemias:

• In lymphoblastic or lymphocytic leukemias Lymphoid leukemia is a type of leukemia affecting circulating cells of lymphoid origin. This is in contrast to lymphoma, which is a solid tumor of lymphoid cells, the cancerous change takes place in a type of marrow cell that normally goes on to form lymphocytes A lymphocyte is a type of white blood cell in the vertebrate immune system, which are infection-fighting immune system cells. Most lymphocytic leukemias involve a specific subtype of lymphocyte, the B cell B cells are lymphocytes that play a large role in the humoral immune response . The principal functions of B cells are to make antibodies against antigens, perform the role of antigen-presenting cells (APCs) and eventually develop into memory B cells after activation by antigen interaction. B cells are an essential component of the adaptive immune.
• In myeloid or myelogenous leukemias, the cancerous change takes place in a type of marrow cell that normally goes on to form red blood cells Red blood cells are the most common type of blood cell and the vertebrate organism's principal means of delivering oxygen (O2) to the body tissues via the blood flow through the circulatory system. They take up oxygen in the lungs or gills and release it while squeezing through the body's capillaries, some other types of white cells, and platelets Platelets, or thrombocytes , are small, irregularly-shaped anuclear cell fragments (i.e. cells that do not have a nucleus containing DNA), 2-3 µm in diameter, which are derived from fragmentation of precursor megakaryocytes. The average lifespan of a platelet is normally just 5 to 9 days. Platelets play a fundamental role in hemostasis and are a.

Combining these two classifications provides a total of four main categories. Within these main categories, there are typically several subcategories. Finally, hairy cell leukemia Hairy cell leukemia is a mature B cell neoplasm. It is usually classified as a sub-type of chronic lymphoid leukemia for convenience. It is uncommon, representing about 2% of all leukemias, or less than a total of 2000 new cases diagnosed each year in North America and Western Europe combined and T-cell prolymphocytic leukemia T-cell-prolymphocytic leukemia is a mature T-cell leukemia with aggressive behavior and predilection for blood, bone marrow, lymph nodes, liver, spleen, and skin involvement. T-PLL is a rare leukemia, primarily affecting adults over the age of 30. It represents 2% of all small lymphocytic leukemias in adults. Other names include: T-cell chronic are usually considered to be outside of this classification scheme.

• Acute lymphoblastic leukemia (ALL) is the most common type of leukemia in young children. This disease also affects adults, especially those age 65 and older. Standard treatments involve chemotherapy and radiation. The survival rates vary by age: 85% in children and 50% in adults.^[3] Subtypes include precursor B acute lymphoblastic leukemia, precursor T acute lymphoblastic leukemia Precursor T acute lymphoblastic leukemia/lymphoma is a form of lymphoid leukemia, Burkitt's leukemia Burkitt lymphoma is a cancer of the lymphatic system (in particular, B lymphocytes). It is named after Denis Parsons Burkitt, a surgeon who first described the disease in 1956 while working in equatorial Africa, and acute biphenotypic leukemia Acute biphenotypic leukaemia is a form of leukaemia where the lineage is of both lymphoid and myeloid origin.
• Chronic lymphocytic leukemia (CLL) most often affects adults over the age of 55. It sometimes occurs in younger adults, but it almost never affects children. Two-thirds of affected people are men. The five-year survival rate is 75%.^[4] It is incurable, but there are many effective treatments. One subtype is B-cell prolymphocytic leukemia B-cell prolymphocytic leukemia is a more aggressive, but still treatable, form of leukemia. The malignant B cells are larger than average. The name is commonly abbreviated B-PLL, a more aggressive disease.
• Acute myelogenous leukemia (AML) occurs more commonly in adults than in children, and more commonly in men than women. AML is treated with chemotherapy. The five-year survival rate is 40%.^[5] Subtypes of AML include acute promyelocytic leukemia Acute promyelocytic leukemia is a subtype of acute myelogenous leukemia , a cancer of the blood and bone marrow. It is also known as acute progranulocytic leukemia; APL; AML with t(15;17)(q22;q12), PML-RARA and variants; FAB subtype M3 and M3 variant, acute myeloblastic leukemia, and acute megakaryoblastic leukemia.
• Chronic myelogenous leukemia (CML) occurs mainly in adults. A very small number of children also develop this disease. Treatment is with imatinib EU EMEA:link, US FDA:link (Gleevec) or other drugs. The five-year survival rate is 90%.^[6][7] One subtype is chronic monocytic leukemia.
• Hairy cell leukemia Hairy cell leukemia is a mature B cell neoplasm. It is usually classified as a sub-type of chronic lymphoid leukemia for convenience. It is uncommon, representing about 2% of all leukemias, or less than a total of 2000 new cases diagnosed each year in North America and Western Europe combined (HCL) is sometimes considered a subset of CLL, but does not fit neatly into this pattern. About 80% of affected people are adult men. There are no reported cases in young children. HCL is incurable, but easily treatable. Survival is 96% to 100% at ten years.^[8]
• T-cell prolymphocytic leukemia T-cell-prolymphocytic leukemia is a mature T-cell leukemia with aggressive behavior and predilection for blood, bone marrow, lymph nodes, liver, spleen, and skin involvement. T-PLL is a rare leukemia, primarily affecting adults over the age of 30. It represents 2% of all small lymphocytic leukemias in adults. Other names include: T-cell chronic (T-PLL) is a very rare and aggressive leukemia affecting adults; somewhat more men than women are diagnosed with this disease.^[9] Despite its overall rarity, it is also the most common type of mature T cell T cells or T lymphocytes belong to a group of white blood cells known as lymphocytes, and play a central role in cell-mediated immunity. They can be distinguished from other lymphocyte types, such as B cells and natural killer cells by the presence of a special receptor on their cell surface called T cell receptors . The abbreviation T, in T cell, leukemia;^[10] nearly all other leukemias involve B cells B cells are lymphocytes that play a large role in the humoral immune response . The principal functions of B cells are to make antibodies against antigens, perform the role of antigen-presenting cells (APCs) and eventually develop into memory B cells after activation by antigen interaction. B cells are an essential component of the adaptive immune. It is difficult to treat, and the median survival is measured in months.
• Large granular lymphocytic leukemia It is sometimes known as "T-cell large granular lymphocyte leukemia" . However, "NK large granular lymphocyte leukemia" (affecting natural killer cells) is also possible may involve either T-cells or NK cells Natural killer cells are a type of cytotoxic lymphocyte that constitute a major component of the innate immune system. NK cells play a major role in the rejection of tumors and cells infected by viruses. The cells kill by releasing small cytoplasmic granules of proteins called perforin and granzyme that cause the target cell to die by apoptosis; like hairy cell leukemia, which involves solely B cells, it is a rare and indolent (not aggressive) leukemia. ^[11]
• Adult T-cell leukemia Human T cell leukemia/lymphotropic virus type 1 is believed to be the cause of it, in addition to several other diseases is caused by human T-lymphotropic virus (HTLV), a virus similar to HIV Human immunodeficiency virus is a lentivirus (a member of the retrovirus family) that causes acquired immunodeficiency syndrome (AIDS), a condition in humans in which the immune system begins to fail, leading to life-threatening opportunistic infections. Infection with HIV occurs by the transfer of blood, semen, vaginal fluid, pre-ejaculate, or. Like HIV, HTLV infects CD4+ T-cells and replicates within them; however, unlike HIV, it does not destroy them. Instead, HTLV "immortalizes" the infected T-cells, giving them the ability to proliferate abnormally.

Signs and 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 Platelets, or thrombocytes , are small, irregularly-shaped anuclear cell fragments (i.e. cells that do not have a nucleus containing DNA), 2-3 µm in diameter, which are derived from fragmentation of precursor megakaryocytes. The average lifespan of a platelet is normally just 5 to 9 days. Platelets play a fundamental role in hemostasis and are a, which are important in the blood clotting process. This means people with leukemia may easily become bruised Purpura is the appearance of red or purple discolorations on the skin that do not blanch on applying pressure. They are caused by bleeding underneath the skin. Purpura measure 0.3-1 cm, whereas petechiae measure less than 3 mm, and ecchymoses greater than 1 cm, bleed Bleeding, technically known as hemorrhaging or haemorrhaging is the loss of blood or blood escape from the circulatory system. Bleeding can occur internally, where blood leaks from blood vessels inside the body or externally, either through a natural opening such as the vagina, mouth, nose, ear or anus, or through a break in the skin. The complete excessively, or develop pinprick bleeds (petechiae A petechia is a small (1-2mm) red or purple spot on the body, caused by a minor hemorrhage (broken capillary blood vessels)).

White blood cells White blood cells , or leukocytes (also spelled "leucocytes"), are cells of the immune system defending the body against both infectious disease and foreign materials. Five different and diverse types of leukocytes exist, but they are all produced and derived from a multipotent cell in the bone marrow known as a hematopoietic stem cell, which are involved in fighting pathogens A pathogen, (from Greek πάθος pathos "suffering, passion", and γἰγνομαι gignomai (gen-) "I give birth to") an infectious agent, or more commonly germ, is a biological agent that causes disease to its host. There are several substrates and pathways whereby pathogens can invade a host; the principal pathways have, 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. Because leukemia prevents the immune system from working normally, some patients experience frequent infection An infection is the detrimental colonization of a host organism by a foreign species. In an infection, the infecting organism seeks to utilize the host's resources to multiply, usually at the expense of the host. The infecting organism, or pathogen, interferes with the normal functioning of the host and can lead to chronic wounds, gangrene, loss, ranging from infected tonsils The tonsils are areas of lymphoid tissue on either side of the throat. An infection of the tonsils is called tonsillitis. Most commonly, the term "tonsils" refers to the palatine tonsils that can be seen in the back of the throat, sores in the mouth, or diarrhea Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and electrolyte imbalances. In 2009 diarrhea was estimated to life-threatening pneumonia Pneumonia is an inflammatory condition of the lung. It is often characterized as including inflammation of the parenchyma of the lung and abnormal alveolar filling with fluid (consolidation and exudation) or opportunistic infections An opportunistic infection is an infection caused by pathogens that usually do not cause disease in a healthy host, i.e. one with a healthy immune system. A compromised immune system, however, presents an "opportunity" for the pathogen to infect.

Finally, the red blood cell deficiency leads to anemia Anemia is a decrease in normal number of red blood cells (RBCs) or less than the normal quantity of hemoglobin in the blood. However, it can include decreased oxygen-binding ability of each hemoglobin molecule due to deformity or lack in numerical development as in some other types of hemoglobin deficiency, which may cause dyspnea Dyspnea or dyspnoea , (from Latin dyspnoea, from Greek dyspnoia from dyspnoos, shortness of breath), also called shortness of breath (SOB) or air hunger, is a debilitating symptom that is the experience of unpleasant or uncomfortable respiratory sensations. It is a common symptom of numerous medical disorders, particularly those involving the and pallor.

Some patients experience other symptoms. These symptoms might include feeling sick Malaise is a feeling of general discomfort or uneasiness, an "out of sorts" feeling, often the first indication of an infection or other disease. Malaise is often defined in medicinal research as a "general feeling of being unwell", such as having fevers, chills, night sweats and other flu-like symptoms, or feeling fatigued. Some patients experience nausea or a feeling of fullness due to an enlarged liver and spleen; this can result in unintentional weight loss. If the leukemic cells invade the central nervous system, then neurological symptoms (notably headaches) can occur.

All symptoms associated with leukemia can be attributed to other diseases. Consequently, leukemia is always diagnosed through medical tests.

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.

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. ^[13]

Causes

No single known cause for all of the different types of leukemia exists. The known causes, which are not generally factors within the control of the average person, account for relatively few cases.^[14] The different leukemias likely have different causes.

Leukemia, like other cancers, results from somatic mutations in the DNA. Certain mutations produce leukemia by activating oncogenes or deactivating tumor suppressor genes, and thereby disrupting the regulation of cell death, differentiation or division. These mutations may occur spontaneously or as a result of exposure to radiation or carcinogenic substances, and are likely to be influenced by genetic factors.^[15]

Among adults, the known causes are natural and artificial ionizing radiation, a few viruses such as Human T-lymphotropic virus, and some chemicals, notably benzene and alkylating chemotherapy agents for previous malignancies.^[16][17][18] Use of tobacco is associated with a small increase in the risk of developing acute myeloid leukemia in adults.^[16] Cohort and case-control studies have linked exposure to some petrochemicals and hair dyes to the development of some forms of leukemia. A few cases of maternal-fetal transmission have been reported.^[16] Diet has very limited or no effect, although eating more vegetables may confer a small protective benefit.^[14]

Viruses have also been linked to some forms of leukemia. Experiments on mice and other mammals have demonstrated the relevance of retroviruses in leukemia, and human retroviruses have also been identified. The first human retrovirus identified was Human T-lymphotropic virus, or HTLV-1, is known to cause adult T-cell leukemia.^[19]

Some people have a genetic predisposition towards developing leukemia. This predisposition is demonstrated by family histories and twin studies.^[16] The affected people may have a single gene or multiple genes in common. In some cases, families tend to develop the same kind of leukemia as other members; in other families, affected people may develop different forms of leukemia or related blood cancers.^[16]

In addition to these genetic issues, people with chromosomal abnormalities or certain other genetic conditions have a greater risk of leukemia.^[17] For example, people with Down syndrome have a significantly increased risk of developing forms of acute leukemia, and Fanconi anemia is a risk factor for developing acute myeloid leukemia.^[16]

Whether non-ionizing radiation causes leukemia has been studied for several decades. The International Agency for Research on Cancer expert working group undertook a detailed review of all data on static and extremely low frequency electromagnetic energy, which occurs naturally and in association with the generation, transmission, and use of electrical power.^[20] They concluded that there is limited evidence that high levels of ELF magnetic (but not electric) fields might cause childhood leukemia. Exposure to significant ELF magnetic fields might result in twofold excess risk for leukemia for children exposed to these high levels of magnetic fields.^[20] However, the report also says that methodological weaknesses and biases in these studies have likely caused the risk to be overstated.^[20] No evidence for a relationship to leukemia or another form of malignancy in adults has been demonstrated.^[20] Since exposure to such levels of ELFs is relatively uncommon, the World Health Organization concludes that ELF exposure, if later proven to be causative, would account for just 100 to 2400 cases worldwide each year, representing 0.2 to 4.95% of the total incidence for that year.^[21]

Diagnosis

Diagnosis is usually based on repeated complete blood counts and a bone marrow examination following symptoms observed. A lymph node biopsy can be performed as well in order to diagnose certain types of leukemia in certain situations. Following diagnosis, blood chemistry tests can be used to determine the degree of liver and kidney damage or the effects of chemotherapy on the patient. When concerns arise about visible damage due to leukemia, doctors may use an X-ray, MRI, or ultrasound. These can potentially view leukemia's effects on such body parts as bones (X-ray), the brain (MRI), or the kidneys, spleen, and liver (ultrasound). Finally, CT scans are rarely used to check lymph nodes in the chest.

Despite the use of these methods to diagnose whether or not a patient has leukemia, many people have not been diagnosed due to the fact that many of the symptoms are vague, unspecific, and can refer to other diseases. For this reason, the American Cancer Society predicts that at least one-fifth of the people with leukemia have not yet been diagnosed. ^[13]

Treatment

Most forms of leukemia are treated with pharmaceutical medications, typically combined into a multi-drug chemotherapy regimen. Some are also treated with radiation therapy. In some cases, a bone marrow transplant is useful.

Acute lymphoblastic leukemia

Management of ALL focuses on control of bone marrow and systemic (whole-body) disease. Additionally, treatment must prevent leukemic cells from spreading to other sites, particularly the central nervous system (CNS) e.g. monthly lumbar punctures. In general, ALL treatment is divided into several phases:

• Induction chemotherapy to bring about bone marrow remission. For adults, standard induction plans include prednisone, vincristine, and an anthracycline drug; other drug plans may include L-asparaginase or cyclophosphamide. For children with low-risk ALL, standard therapy usually consists of three drugs (prednisone, L-asparaginase, and vincristine) for the first month of treatment.
• Consolidation therapy or intensification therapy to eliminate any remaining leukemia cells. There are many different approaches to consolidation, but it is typically a high-dose, multi-drug treatment that is undertaken for a few months. Patients with low- to average-risk ALL receive therapy with antimetabolite drugs such as methotrexate and 6-mercaptopurine (6-MP). High-risk patients receive higher drug doses of these drugs, plus additional drugs.
• CNS prophylaxis (preventive therapy) to stop the cancer from spreading to the brain and nervous system in high-risk patients. Standard prophylaxis may include radiation of the head and/or drugs delivered directly into the spine.
• Maintenance treatments with chemotherapeutic drugs to prevent disease recurrence once remission has been achieved. Maintenance therapy usually involves lower drug doses, and may continue for up to three years.
• Alternatively, allogeneic bone marrow transplantation may be appropriate for high-risk or relapsed patients. ^[22]

Chronic lymphocytic leukemia

Decision to treat Hematologists base CLL treatment on both the stage and symptoms of the individual patient. A large group of CLL patients have low-grade disease, which does not benefit from treatment. Individuals with CLL-related complications or more advanced disease often benefit from treatment. In general, the indications for treatment are:

• Falling hemoglobin or platelet count
• Progression to a later stage of disease
• Painful, disease-related overgrowth of lymph nodes or spleen
• An increase in the rate of lymphocyte production ^[23]

Typical treatment approach CLL is probably incurable by present treatments. The primary chemotherapeutic plan is combination chemotherapy with chlorambucil or cyclophosphamide, plus a corticosteroid such as prednisone or prednisolone. The use of a corticosteroid has the additional benefit of suppressing some related autoimmune diseases, such as immunohemolytic anemia or immune-mediated thrombocytopenia. In resistant cases, single-agent treatments with nucleoside drugs such as fludarabine, ^[24] pentostatin, or cladribine may be successful. Younger patients may consider allogeneic or autologous bone marrow transplantation. ^[25]

Acute myelogenous leukemia

Many different anti-cancer drugs are effective for the treatment of AML. Treatments vary somewhat according to the age of the patient and according to the specific subtype of AML. Overall, the strategy is to control bone marrow and systemic (whole-body) disease, while offering specific treatment for the central nervous system (CNS), if involved.

In general, most oncologists rely on combinations of drugs for the initial, induction phase of chemotherapy. Such combination chemotherapy usually offers the benefits of early remission and a lower risk of disease resistance. Consolidation and maintenance treatments are intended to prevent disease recurrence. Consolidation treatment often entails a repetition of induction chemotherapy or the intensification chemotherapy with additional drugs. By contrast, maintenance treatment involves drug doses that are lower than those administered during the induction phase. ^[26]

Chronic myelogenous leukemia

There are many possible treatments for CML, but the standard of care for newly diagnosed patients is imatinib (Gleevec) therapy.^[27] Compared to most anti-cancer drugs, it has relatively few side effects and can be taken orally at home. With this drug, more than 90% of patients will be able to keep the disease in check for at least five years,^[27] so that CML becomes a chronic, manageable condition.

In a more advanced, uncontrolled state, when the patient cannot tolerate imatinib, or if the patient wishes to attempt a permanent cure, then an allogeneic bone marrow transplantation may be performed. This procedure involves high-dose chemotherapy and radiation followed by infusion of bone marrow from a compatible donor. Approximately 30% of patients die from this procedure.^[27]

Hairy cell leukemia

Decision to treat Patients with hairy cell leukemia who are symptom-free typically do not receive immediate treatment. Treatment is generally considered necessary when the patient shows signs and symptoms such as low blood cell counts (e.g., infection-fighting neutrophil count below 1.0 K/µL), frequent infections, unexplained bruises, anemia, or fatigue that is significant enough to disrupt the patient's everyday life.

Typical treatment approach Patients who need treatment usually receive either one week of cladribine, given daily by intravenous infusion or a simple injection under the skin, or six months of pentostatin, given every four weeks by intravenous infusion. In most cases, one round of treatment will produce a prolonged remission. ^[28]

Other treatments include rituximab infusion or self-injection with Interferon-alpha. In limited cases, the patient may benefit from splenectomy (removal of the spleen). These treatments are not typically given as the first treatment because their success rates are lower than cladribine or pentostatin. ^[29]

T-cell prolymphocytic leukemia

Most patients with T-cell prolymphocytic leukemia, a rare and aggressive leukemia with a median survival of less than one year, require immediate treatment.^[30]

T-cell prolymphocytic leukemia is difficult to treat, and it does not respond to most available chemotherapeutic drugs.^[30] Many different treatments have been attempted, with limited success in certain patients: purine analogues (pentostatin, fludarabine, cladribine), chlorambucil, and various forms of combination chemotherapy (cyclophosphamide, doxorubicin, vincristine, prednisone CHOP, cyclophosphamide, vincristine, prednisone [COP], vincristine, doxorubicin, prednisone, etoposide, cyclophosphamide, bleomycin VAPEC-B). Alemtuzumab (Campath), a monoclonal antibody that attacks white blood cells, has been used in treatment with greater success than previous options.^[30]

Some patients who successfully respond to treatment also undergo stem cell transplantation to consolidate the response.^[30]

Juvenile myelomonocytic leukemia

Treatment for juvenile myelomonocytic leukemia can include splenectomy, chemotherapy, and bone marrow transplantation.^[31]

Epidemiology

In 2000, approximately 256,000 children and adults around the world developed a form of leukemia, and 209,000 died from it.^[1] This represents about 3% of the almost seven million deaths due to cancer that year, and about 0.35% of all deaths from any cause.^[1] Of the sixteen separate sites the body compared, leukemia was the 12th most common class of neoplastic disease, and the 11th most common cause of cancer-related death.^[1]

About 245,000 people in the United States are affected with some form of leukemia, including those that have achieved remission or cure. Approximately 44,270 new cases of leukemia were diagnosed in the year of 2008 in the US.^[2] This represents 2.9% of all cancers (excluding simple basal cell and squamous cell skin cancers) in the United States, and 30.4% of all blood cancers.^[33]

Among children with some form of cancer, about a third have a type of leukemia, most commonly acute lymphoblastic leukemia.^[2] Only about 3% cancer diagnoses among adults are for leukemias, but because cancer is much more common among adults, more than 90% of all leukemias are diagnosed in adults.^[2]

History

Leukemia was first observed by pathologists Rudolf Virchow and John Hughes Bennett in 1885. Observing an abnormally large amount of white blood cells in a blood sample from a patient, Virchow called the condition "Leukemia", meaning "White Blood". Around ten years after Virchow and Bennett's findings, pathologist Franz Ernst Christian Neumann found that one deceased leukemia patient's bone marrow was colored "dirty green-yellow" as opposed to the normal red. This finding allowed Neumann to conclude that a bone marrow problem was responsible for the abnormal blood of leukemia patients.

Due to a heightened understanding of leukemia, by 1900 leukemia was viewed as a family of diseases as opposed to a single disease. By 1947 Boston pathologist Sydney Farber believed from past experiments that aminopterin, a folic acid mimic, could potentially cure leukemia in children. The majority of the children with ALL who were tested showed signs of improvement in their bone marrow, but none of them actually were cured. This, however, led to further experiments.

In 1962, researchers Emil J. Freireich Jr. and Emil Frei III used combination chemotherapy to attempt to cure leukemia. The tests were successful with some patients surviving long after the tests. ^[34]

Research

Significant research into the causes, diagnosis, treatment, and prognosis of leukemia is being performed. Hundreds of clinical trials are being planned or conducted at any given time.^[35] Studies may focus on effective means of treatment, better ways of treating the disease, improving the quality of life for patients, or appropriate care in remission or after cures. In general research in the area of leukemia can be divided into two types of research: Clinical/Translational research and Basic Science research. Clinical/translational research focuses on studying the disease in a defined and generally immediately patient applicable way; whereas Basic Science research studies the disease process at a distance and the results from such studies are generally less immediately useful to patients with the disease.^[36]

See also :

• Chronic_lymphocytic_leukemia#Treatment
• Hairy_cell_leukemia#Research_directions

See also

• Acute erythroid leukemia
• Antileukemic drugs, medications used to kill leukemia cells
• Hematologic diseases, the large class of blood-related disorders, including leukemia

References

1. ^ ^{a b c d} Mathers, Colin D, Cynthia Boschi-Pinto, Alan D Lopez and Christopher JL Murray (2001). "Cancer incidence, mortality and survival by site for 14 regions of the world.". Global Programme on Evidence for Health Policy Discussion Paper No. 13 (World Health Organization). http://www.who.int/entity/healthinfo/paper13.pdf.
2. ^ ^{a b c d} "Leukemia Facts & Statistics." The Leukemia & Lymphoma Society. Accessed 2009-07-02.
3. ^ Jameson, J. N. St C.; Dennis L. Kasper; Harrison, Tinsley Randolph; Braunwald, Eugene; Fauci, Anthony S.; Hauser, Stephen L; Longo, Dan L. (2005). Harrison's principles of internal medicine. New York: McGraw-Hill Medical Publishing Division. ISBN 0-07-140235-7.
4. ^ Finding Cancer Statistics » Cancer Stat Fact Sheets »Chronic Lymphocytic Leukemia National Cancer Institute.
5. ^ Colvin GA, Elfenbein GJ (2003). "The latest treatment advances for acute myelogenous leukemia". Med Health R I 86 (8): 243–6. PMID 14582219.
6. ^ Patients with Chronic Myelogenous Leukemia Continue to Do Well on Imatinib at 5-Year Follow-Up Medscape Medical News 2006.
7. ^ Updated Results of Tyrosine Kinase Inhibitors in CML ASCO 2006 Conference Summaries.
8. ^ Else M, Ruchlemer R, Osuji N (2005). "Long remissions in hairy cell leukemia with purine analogs: a report of 219 patients with a median follow-up of 12.5 years". Cancer 104 (11): 2442–8. doi:10.1002/cncr.21447. PMID 16245328.
9. ^ Matutes, Estella. (1998) "T-cell prolymphocytic leukemia, a rare variant of mature post-thymic T-cell leukemias, has distinct clinical and laboratory characteristics and a poor prognosis." Cancer Control Journal Volume 5 Number 1.
10. ^ Valbuena JR, Herling M, Admirand JH, Padula A, Jones D, Medeiros LJ (March 2005). "T-cell prolymphocytic leukemia involving extramedullary sites". Am. J. Clin. Pathol. 123 (3): 456–64. doi:10.1309/93P4-2RNG-5XBG-3KBE. PMID 15716243. http://www.medscape.com/viewarticle/501092.
11. ^ Elaine Sarkin Jaffe, Nancy Lee Harris, World Health Organization, International Agency for Research on Cancer, Harald Stein, J.W. Vardiman (2001). Pathology and genetics of tumours of haematopoietic and lymphoid tissues. World Health Organization Classification of Tumors. 3. Lyon: IARC Press. ISBN 92-832-2411-6. http://books.google.com/?id=XSKqcy7TUZUC.
12. ^ Reference list is found at image description page in Wikimedia Commons
13. ^ ^{a b} American Cancer Society (2010). "How is Leukemia Diagnosed?". Detailed Guide: Leukemia - Adult Chronic. American Cancer Society. http://www.cancer.org/docroot/cri/content/cri_2_4_3x_how_is_leukemia_diagnosed_62.asp. Retrieved 4 May 2010.
14. ^ ^{a b} Ross JA, Kasum CM, Davies SM, Jacobs DR, Folsom AR, Potter JD (August 2002). "Diet and risk of leukemia in the Iowa Women's Health Study". Cancer Epidemiol. Biomarkers Prev. 11 (8): 777–81. PMID 12163333. http://cebp.aacrjournals.org/content/11/8/777.long.
15. ^ "Do We Know What Causes Leukemia". Detailed Guide: Leukemia. American Cancer Society. 2010. http://www.cancer.org/docroot/CRI/content/CRI_2_4_2X_Do_we_know_what_causes_leukemia_62.asp. Retrieved 18 May 2010.
16. ^ ^{a b c d e f} Wiernik, Peter H. (2001). Adult leukemias. New York: B. C. Decker. pp. 3–15. ISBN 1-55009-111-5.
17. ^ ^{a b} Robinette, Martin S.; Cotter, Susan; Van de Water (2001). Quick Look Series in Veterinary Medicine: Hematology. Teton NewMedia. p. 105. ISBN 1-893441-36-9.
18. ^ Stass, Sanford A.; Schumacher, Harold R.; Rock, William R. (2000). Handbook of hematologic pathology. New York, N.Y: Marcel Dekker. pp. 193–194. ISBN 0-8247-0170-4.
19. ^ Leonard, Barry (1998). Leukemia: A Research Report. DIANE Publishing. pp. 14. ISBN 0788171895. http://books.google.com/?id=VfFCVvX9btYC&printsec=frontcover&dq=leukemia&q.
20. ^ ^{a b c d} Non-Ionizing Radiation, Part 1: Static and Extremely Low-Frequency (ELF) Electric and Magnetic Fields (IARC Monographs on the Evaluation of the Carcinogenic Risks). Geneva: World Health Organisation. 2002. pp. 332–333, 338. ISBN 92-832-1280-0. http://monographs.iarc.fr/ENG/Monographs/vol80/index.php.
21. ^ "WHO | Electromagnetic fields and public health". http://www.who.int/mediacentre/factsheets/fs322/en/index.html. Retrieved 2009-02-18.
22. ^ Hoffbrand AV, Moss PAH, and Pettit JE, "Essential Haematology", Blackwell, 5th ed., 2006.
23. ^ National Cancer Institute. "Chronic Lymphocytic Leukemia (PDQ) Treatment: Stage Information". http://www.cancer.gov/cancertopics/pdq/treatment/CLL/HealthProfessional/page2. Retrieved 2007-09-04.
24. ^ Eichhorst BF, Busch R, Hopfinger G, Pasold R, Hensel M, Steinbrecher C, Siehl S, Jäger U, Bergmann M, Stilgenbauer S, Schweighofer C, Wendtner CM, Döhner H, Brittinger G, Emmerich B, Hallek M, German CLL Study Group. (2006). "Fludarabine plus cyclophosphamide versus fludarabine alone in first-line therapy of younger patients with chronic lymphocytic leukemia". Blood 107 (3): 885–91.. doi:10.1182/blood-2005-06-2395. PMID 16219797.
25. ^ Gribben JG (January 2008). "Stem cell transplantation in chronic lymphocytic leukemia". Biol. Blood Marrow Transplant. 15 (1 Suppl): 53–8. doi:10.1016/j.bbmt.2008.10.022. PMID 19147079.
26. ^ American Cancer Society (6 July 2009). "Typical Treatment of Acute Myeloid Leukemia". Detailed Guide: Leukemia - Acute Myeloid (AML). American Cancer Society. http://www.cancer.org/docroot/CRI/content/CRI_2_4_4x_Treatment_of_Acute_Myeloid_Leukemia_AML.asp. Retrieved 4 May 2010.
27. ^ ^{a b c} Fausel C (October 2007). "Targeted chronic myeloid leukemia therapy: seeking a cure". J Manag Care Pharm 13 (8 Suppl A): 8–12. PMID 17970609. http://www.amcp.org/data/jmcp/pages%208-12.pdf.
28. ^ "Cladribine in a weekly versus daily schedule for untreated active hairy cell leukemia: final report from the Polish Adult Leukemia Group (PALG) of a prospective, randomized, multicenter trial -- Robak et al. 109 (9): 3672 -- Blood". http://bloodjournal.hematologylibrary.org/cgi/content/abstract/bloodjournal;109/9/3672. Retrieved 2007-09-10.
29. ^ "Filgrastim for Cladribine-Induced Neutropenic Fever in Patients With Hairy Cell Leukemia -- Saven et al. 93 (8): 2471 -- Blood". http://bloodjournal.hematologylibrary.org/cgi/content/full/93/8/2471. Retrieved 2007-09-10.
30. ^ ^{a b c d} Dearden CE, Matutes E, Cazin B (September 2001). "High remission rate in T-cell prolymphocytic leukemia with CAMPATH-1H". Blood 98 (6): 1721–6. doi:10.1182/blood.V98.6.1721. PMID 11535503. http://www.bloodjournal.org/cgi/pmidlookup?view=long&pmid=11535503.
31. ^ JMMLfoundation.org
32. ^ "WHO Disease and injury country estimates". World Health Organization. 2009. http://www.who.int/healthinfo/global_burden_disease/estimates_country/en/index.html. Retrieved 2009-11-11.
33. ^ Horner MJ, Ries LAG, Krapcho M, Neyman N, et al. (eds).. "SEER Cancer Statistics Review, 1975–2006". Surveillance Epidemiology and End Results (SEER). Bethesda, MD: National Cancer Institute. http://seer.cancer.gov/csr/1975_2006/. Retrieved 2009-11-03. "Table 1.4: Age-Adjusted SEER Incidence and U.S. Death Rates and 5-Year Relative Survival Rates By Primary Cancer Site, Sex and Time Period"
34. ^ Patlak, Margie. "Targeting Leukemia: From Bench to Bedside". Breakthroughs in Bioscience. The Federation of American Societies for Experimental Biology. http://opa1.faseb.org/pdf/leukemia.pdf. Retrieved 20 May 2010.
35. ^ http://www.clinicaltrials.gov/ct2/results?term=leukemia
36. ^ "Understanding Clinical Trials for Blood Cancers". Leukemia and Lymphoma Society. http://www.leukemia-lymphoma.org/attachments/National/br_1162487596.pdf. Retrieved 19 May 2010.

External links

• Leukemia at the Open Directory Project

Categories: Leukemia | Hematology | Types of cancer | Blood disorders | Hematopathology

See Also:

What Links Here:

Recently Viewed Pages:

• Shopping: Food: Produce: Vegetables: Sea Vegetables: Directory
• Ergonomics: Encyclopedia
• Home
• DASH Diet
• Healthy Diet: Images
• Copper
• Nutrition
• Images
• Shopping: Food: Health Food: Grains: Directory
• Shopping: Health: Nutrition: Green Foods: Directory

Most Popular Pages:

• Home
• Healthy Diet Pyramid: Images
• Tony Gonzalez the All-Pro Diet: News
• Ice Cream: Encyclopedia
• Fitness
• Bean: Answers
• BMI
• Forensic Pathologist: Answers
• Seed: Encyclopedia
• Search Terms

Related 'Leukemia' Searches: