Leukemia (British English: leukaemia) (Greek leukos λευκός, "white"; aima αίμα, "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). 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.
CAUSE
Leukemia cells are usually of white blood cells.
The cause of most types of leukemia is unknown.
The virus causing leukemia in some animals (eg cats).
Leukemia cells are usually of white blood cells.
The cause of most types of leukemia is unknown.
The virus causing leukemia in some animals (eg cats).
Viruses HTLV-I (human T-cell lymphotropic virus type I), which resembles the virus that causes AIDS, is thought to cause a rare type of leukemia in humans, namely T-cell adult leukemia.
Exposure to radiation (radiation) and certain chemicals (eg benzene) and the use of anticancer drugs, increases the risk of leukemia.
People who have certain genetic disorders (such as Down syndrome and Fanconi syndrome), are also more susceptible to leukemia.
These changes often involve the rearrangement of parts of chromosomes (genetic material of complex cells).
Chromosome rearrangement (translocation chromosomes) disrupt the normal control of cell division, so that cells divide uncontrollably and become malignant.
In the end these cells over bone marrow and replace the cells that produce blood cells normally.
This cancer can also infiltrate into other organs, including liver, spleen, lymph nodes, kidneys and brain.
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
There are many possible treatments for CML, but the standard of care for newly diagnosed patients is imatinib (Gleevec) therapy. 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, 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.
People who have certain genetic disorders (such as Down syndrome and Fanconi syndrome), are also more susceptible to leukemia.
These changes often involve the rearrangement of parts of chromosomes (genetic material of complex cells).
Chromosome rearrangement (translocation chromosomes) disrupt the normal control of cell division, so that cells divide uncontrollably and become malignant.
In the end these cells over bone marrow and replace the cells that produce blood cells normally.
This cancer can also infiltrate into other organs, including liver, spleen, lymph nodes, kidneys and brain.
There are 4 main types of leukemia, which are named based on the speed of progression of the disease and the type of white blood cell affected:
Most forms of leukemia are treated with pharmaceutical medications. Some are also treated with radiation therapy. In some cases, a bone marrow transplant is useful.
Acute lymphoblastic leukemia (ALL)
Progresion : FAST
White blood cells infected : Limfosit
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.
Acute Myelogenous Leukemia (AML)
(mielositik, mielogenous, mieloblastik, mielomonositik)
Progresion : FAST
White blood cells infected : MielositMany 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.
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.
Chronic lymphocytic leukemia (CLL)
(including the Sezary syndrome and hairy cell leukemia)
(including the Sezary syndrome and hairy cell leukemia)
Progresion : SLOW
White blood cells infected : Limfosit
Decision to treat
Hematologists base CLL treatment upon 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:
Hematologists base CLL treatment upon 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
- Typical treatment approach
Chronic myelogenous leukemia (CML)
(mieloid, mielogenous, granulositik)
Progresion : SLOW
White blood cells infected : Mielosit There are many possible treatments for CML, but the standard of care for newly diagnosed patients is imatinib (Gleevec) therapy. 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, 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.
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