Leukemia: symptoms Causes Types and Treatment.

Leukemia is a cancer of the blood cells that affects the blood and bone marrow. Leukemia begins in a cell in the bone marrow. The cell undergoes a change and becomes a type of leukemia cell. Once the marrow cell undergoes a leukemic change, the leukemia cells may grow and survive better than normal cells. Over time, the leukemia cells crowd out or suppress the development of normal cells. The rate at which leukemia progresses and how the cells replace the normal blood and marrow cells are different with each type of leukemia.

Leukemia usually involves the white blood cells. Your white blood cells are potent infection fighters — they normally grow and divide in an orderly way, as your body needs them. But in people with leukemia, the bone marrow produces abnormal white blood cells, which don't function properly.

Many types of leukemia exist. Some forms of leukemia are more common in children. Other forms of leukemia occur mostly in adults.

Symptoms of Leukemia 

Leukemia symptoms vary, depending on the type of leukemia. 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

How leukemia forms

In general, leukemia is thought to occur when some blood cells acquire mutations in their DNA — the instructions inside each cell that guide its action. There may be other changes in the cells that have yet to be fully understood that could contribute to leukemia.

Certain abnormalities cause the cell to grow and divide more rapidly and to continue living when normal cells would die. Over time, these abnormal cells can crowd out healthy blood cells in the bone marrow, leading to fewer healthy white blood cells, red blood cells and platelets, causing the signs and symptoms of leukemia.

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.

Other types. Other, rarer types of leukemia exist, including hairy cell leukemia, myelodysplastic syndromes and myeloproliferative disorders.
Risk factors

Factors that may increase your risk of developing some types of leukemia include:

• Previous cancer treatment. People who've had certain types of chemotherapy and radiation therapy for other cancers have an increased risk of developing certain types of leukemia.
• Genetic disorders. Genetic abnormalities seem to play a role in the development of leukemia. Certain genetic disorders, such as Down syndrome, are associated with an increased risk of leukemia.
• Exposure to certain chemicals. Exposure to certain chemicals, such as benzene — which is found in gasoline and is used by the chemical industry — is linked to an increased risk of some kinds of leukemia.
• Smoking. Smoking cigarettes increases the risk of acute myelogenous leukemia.
• Family history of leukemia. If members of your family have been diagnosed with leukemia, your risk of the disease may be increased.

Diagnosing leukemia

Leukemia may be suspected if you have certain risk factors or concerning symptoms. Your doctor will begin with a complete history and physical examination, but leukemia can’t be fully diagnosed by a physical exam. Instead, doctors will use blood tests, biopsies, and imaging tests to make a diagnosis.

Tests

There are a number of different tests that can be used to diagnose leukemia. A complete blood count determines the numbers of RBCs, WBCs, and platelets in the blood. Looking at your blood under a microscope can also determine if the cells have an abnormal appearance.

Tissue biopsiescan be taken from the bone marrow or lymph nodes to look for evidence of leukemia. These small samples can identify the type of leukemia and its growth rate. Biopsies of other organs such as the liver and spleen can show if the cancer has spread.

Staging

Once leukemia is diagnosed, it’ll be staged. Staging helps your doctor determine your outlook.

AML and ALL are staged based on how cancer cells look under the microscope and the type of cell involved. ALL and CLL are staged based on the WBC count at the time of diagnosis. The presence of immature white blood cells, or myeloblasts, in the blood and bone marrow is also used to stage AML and CML.

Assessing the progression

A number of other tests can be used to assess the progression of the disease:

Flow cytometry examines the DNA of the cancer cells and determines their growth rate.
Liver function tests show whether leukemia cells are affecting or invading the liver.
Lumbar puncture is performed by inserting a thin needle between the vertebrae of your lower back. This allows your doctor to collect spinal fluid and determine if the cancer has spread to the central nervous system.
Imaging tests, such as X-rays, ultrasounds, and CT scans, help doctors look for any damage to other organs that’s caused by the leukemia.

Treating leukemia

Leukemia is usually treated by a hematologist-oncologist. These are doctors who specialize in blood disorders and cancer. The treatment depends on the type and stage of the cancer. Some forms of leukemia grow slowly and don’t need immediate treatment. However, treatment for leukemia usually involves one or more of the following:

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• Chemotherapy uses drugs to kill leukemia cells. Depending on the type of leukemia, you may take either a single drug or a combination of different drugs.
• Radiation therapy uses high-energy radiation to damage leukemia cells and inhibit their growth. Radiation can be applied to a specific area or to your entire body.
• Stem cell transplantation replaces diseased bone marrow with healthy bone marrow, either your own (called autologous transplantation) or from a donor (called allologous transplantation). This procedure is also called a bone marrow transplant.
• Biological or immune therapy uses treatments that help your immune system recognize and attack cancer cells.
• Targeted therapy uses medications that take advantage of vulnerabilities in cancer cells. For example, imatinib (Gleevec) is a targeted drug that’s commonly used against CML.