Overview

Leukemia is cancer that starts in the tissue that forms blood. To understand cancer, it helps to know how normal blood cells form. Most blood cells develop from cells in the bone marrow called stem cells. Bone marrow is the soft material in the center of most bones.
Stem cells mature into different kinds of blood cells. Each kind has a special job:
White blood cells help fight infection. There are several types of white blood cells.
Red blood cells carry oxygen to tissues throughout the body.
Platelets help form blood clots that control bleeding.
White blood cells, red blood cells, and platelets are made from stem cells as the body needs them. When cells grow old or get damaged, they die, and new cells take their place.

In a person with leukemia, the bone marrow makes abnormal white blood cells. The abnormal cells are leukemia cells. Unlike normal blood cells, leukemia cells don't die when they should. They may crowd out normal white blood cells, red blood cells, and platelets. This makes it hard for normal blood cells to do their work.

Types of Leukemia

The types of leukemia can be grouped based on how quickly the disease develops and gets worse. Leukemia is either chronic (which usually gets worse slowly) or acute (which usually gets worse quickly):

Chronic leukemia:

Early in the disease, the leukemia cells can still do some of the work of normal white blood cells. People may not have any symptoms at first. Doctors often find chronic leukemia during a routine checkup - before there are any symptoms. Slowly, chronic leukemia gets worse. As the number of leukemia cells in the blood increases, people get symptoms, such as swollen lymph nodes or infections. When symptoms do appear, they are usually mild at first and get worse gradually.

Acute leukemia:

The leukemia cells can't do any of the work of normal white blood cells. The number of leukemia cells increases rapidly. Acute leukemia usually worsens quickly.

The types of leukemia also can be grouped based on the type of white blood cell that is affected. Leukemia can start in lymphoid cells or myeloid cells. See the picture of these cells. Leukemia that affects lymphoid cells is called lymphoid, lymphocytic, or lymphoblastic leukemia. Leukemia that affects myeloid cells is called myeloid, myelogenous, or myeloblastic leukemia.

There are four common types of leukemia:

Chronic lymphocytic leukemia (CLL):

CLL affects lymphoid cells and usually grows slowly. It accounts for more than 15,000 new cases of leukemia each year. Most often, people diagnosed with the disease are over age 55. It almost never affects children.

Chronic myeloid leukemia (CML):

CML affects myeloid cells and usually grows slowly at first. It accounts for nearly 5,000 new cases of leukemia each year. It mainly affects adults.

Acute lymphocytic (lymphoblastic) leukemia (ALL):

ALL affects lymphoid cells and grows quickly. It accounts for more than 5,000 new cases of leukemia each year. ALL is the most common type of leukemia in young children. It also affects adults.

Acute myeloid leukemia (AML):

AML affects myeloid cells and grows quickly. It accounts for more than 13,000 new cases of leukemia each year. It occurs in both adults and children.

What are the symptoms of leukemia?

Like all blood cells, leukemia cells travel through the body. The symptoms of leukemia depend on the number of leukemia cells and where these cells collect in the body.

People with chronic leukemia may not have symptoms. The doctor may find the disease during a routine blood test.

People with acute leukemia usually go to their doctor because they feel sick. If the brain is affected, they may have headaches, vomiting, confusion, loss of muscle control, or seizures. Leukemia also can affect other parts of the body such as the digestive tract, kidneys, lungs, heart, or testes.

Common symptoms of chronic or acute leukemia may include:

-Swollen lymph nodes that usually don't hurt (especially lymph nodes in the neck or armpit)

When to seek Urgent Medical Care?

If you have leukemia, and have received chemotherapy, you may develop a fever that may reflect the fact that your blood counts are low and you should seek medical care for antibiotics.

Diagnosis

Doctors sometimes find leukemia after a routine blood test. If you have symptoms that suggest leukemia, your doctor will try to find out what's causing the problems. Your doctor may ask about your personal and family medical history.

Blood tests: The lab does a complete blood count to check the number of white blood cells, red blood cells, and platelets. Leukemia causes a very high level of white blood cells. It may also cause low levels of platelets and hemoglobin, which is found inside red blood cells.

Biopsy: Your doctor removes tissue to look for cancer cells. A biopsy is the only sure way to know whether leukemia cells are in your bone marrow. Before the sample is taken, local anesthesia is used to numb the area. This helps reduce the pain. Your doctor removes some bone marrow from your hipbone or another large bone. A pathologist uses a microscope to check the tissue for leukemia cells.

The tests that your doctor orders for you depend on your symptoms and type of leukemia. You may have other, less common tests:

Cytogenetics: The lab looks at the chromosomes of cells from samples of blood, bone marrow, or lymph nodes. If abnormal chromosomes are found, the test can show what type of leukemia you have. For example, people with CML have an abnormal chromosome called the Philadelphia chromosome.

Spinal tap: Your doctor may remove some of the cerebrospinal fluid (the fluid that fills the spaces in and around the brain and spinal cord). The doctor uses a long, thin needle to remove fluid from the lower spine. The procedure takes about 30 minutes and is performed with local anesthesia. You must lie flat for several hours afterward to keep from getting a headache. The lab checks the fluid for leukemia cells or other signs of problems.

Chest x-ray: An x-ray can show swollen lymph nodes or other signs of disease in your chest.

Treatment Options

Unlike other types of cancer, leukemia isn't a tumor that your doctor can surgically remove. Leukemia cells are produced in the bone marrow and travel throughout the body.
There are several treatment options for leukemia. Every treatment option has side effects and drawbacks. Be sure to consult with your doctor about which one is right for you.

Radiation Therapy:

Radiation therapy (also called radiotherapy) uses high-energy rays to kill leukemia cells. People receive radiation therapy at a hospital or clinic. Some people receive radiation from a large machine that is aimed at the spleen, the brain, or other parts of the body where leukemia cells have collected. For more information see Radiation therapy

Chemotherapy:

Many people with leukemia are treated with chemotherapy. Chemotherapy uses drugs to destroy leukemia cells. For more information see Chemotherapy.

Biological Therapy:

Biological therapy uses special substances that improve the body's natural defenses against cancer. Some patients with chronic lymphocytic leukemia receive monoclonal antibodies, which are man-made proteins that can identify leukemia cells. Monoclonal antibodies bind to the cells and assist the body in killing them.

Targeted Therapy:

People with chronic myeloid leukemia and some with acute lymphoblastic leukemia may receive drugs called targeted therapy.Targeted therapies use drugs that block the growth of leukemia cells. For example, a targeted therapy may block the action of an abnormal protein that stimulates the growth of leukemia cells.

Stem Cell Transplant:

Some people with leukemia receive a stem cell transplant. A stem cell transplant allows you to be treated with high doses of drugs, radiation, or both. The high doses destroy both leukemia cells and normal blood cells in the bone marrow. After you receive highdose chemotherapy, radiation therapy, or both, you receive healthy stem cells through a large vein. (It's like getting a blood transfusion.) New blood cells develop from the transplanted stem cells. The new blood cells replace the ones that were destroyed by treatment.

Diseases with similar symptoms

Where to get Medical Care for leukemia?

Prevention

There are certain activities and events which can lead to an increased risk for leukemia. Try to avoid:

-Smoking

-Exposure to the chemical Benzene

-Exposure to large amounts of radiation

Other factors that point to a higher risk for leukemia include:
-Chemotherapy
-Down syndrome and certain other inherited diseases
-Myelodysplastic syndrome and certain other blood disorders
-Family history of leukemia
-Infection with the Human T-cell leukemia virus type I (HTLV-I)

What to Expect (Outook/Prognosis)?

Leukemia is a very serious disease which can have many complications. Complications can come from the disease itself and the treatments. Acute leukemia has a much quicker and more dramatic onset, but can sometimes be cured. Chronic Leukiemia has a slower onset and can often be put off for years. However, chronic leukemia is very rarely cured.