What Is Leukaemia?
Leukaemia is cancer of the body’s blood-forming tissues, including the bone marrow and the lymphatic system. Leukaemia 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 leukaemia, the bone marrow produces an excessive amount of abnormal white blood cells, which don’t function properly.
Different types of leukaemia can cause different problems. You might not notice any signs in the early stages of some forms. When you do have symptoms, they may include:
- Weakness or fatigue
- Bruising or bleeding easily
- Fever or chills
- Infections that are severe or keep coming back
- Pain in your bones or joints
- Weight loss
- Night sweats
- Shortness of breath
- Swollen lymph nodes or organs like your spleen
Leukemia Causes and Risk Factors
No one knows exactly what causes leukemia. People who have it have certain unusual chromosomes, but the chromosomes don’t cause leukemia.
You can’t prevent leukemia, but certain things may trigger it. You might have a higher risk if you:
- 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.
How does leukemia happen?
- Blood has three types of cells: white blood cells that fight infection, red blood cells that carry oxygen, and platelets that help blood clot.
- Every day, your bone marrow makes billions of new blood cells, and most of them are red cells. When you have leukemia, your body makes more white cells than it needs.
- These leukemia cells can’t fight infection the way normal white blood cells do. And because there are so many of them, they start to affect the way your organs work. Over time, you may not have enough red blood cells to supply oxygen, enough platelets to clot your blood, or enough normal white blood cells to fight infection.
Leukemia is grouped by how fast it develops and gets worse, and by which type of blood cell is involved.
The first group, how fast it develops, is divided into acute and chronic leukemia.
- Acute leukemia happens when most of the abnormal blood cells don’t mature and can’t carry out normal functions. It can get bad very fast.
- Chronic leukemia happens when there are some immature cells, but others are normal and can work the way they should. It gets bad more slowly than acute forms do.
The second group, what type of cell is involved, is divided into lymphocytic and myelogenous leukemia.
- Lymphocytic (or lymphoblastic) leukemia involves bone marrow cells that become lymphocytes, a kind of white blood cell.
- Myelogenous (or myeloid) leukemia involves the marrow cells that create red blood cells, platelets, and other kinds of white blood cells.
Types of leukemia
The four main types of leukemia are:
- Acute lymphocytic leukemia (ALL)-This is the most common form of childhood leukemia. It can spread to your lymph nodes and central nervous system.
- Acute myelogenous leukemia (AML)- This is the second most common form of childhood leukemia and one of the most common forms for adults.
- Chronic lymphocytic leukemia (CLL)- This is the other most common form of adult leukemia. Some kinds of CLL will be stable for years and won’t need treatment. But with others, your body isn’t able to create normal blood cells, and you’ll need treatment.
- Chronic myelogenous leukemia (CML)- With this form, you might not have noticeable symptoms. You might not be diagnosed with it until you have a routine blood test. People 65 and older have a higher risk of this type.
Doctor will need to check for signs of leukemia in blood or bone marrow. They might do tests including:
- Blood tests. A complete blood count (CBC) looks at the number and maturity of different types of blood cells. A blood smear looks for unusual or immature cells.
- Bone marrow biopsy. This test involves marrow taken from your pelvic bone with a long needle. It can tell your doctor what kind of leukaemia you have and how severe it is.
- Spinal tap. This involves fluid from your spinal cord. It can tell your doctor whether the leukaemia has spread.
- Imaging tests. Things like CT, MRI, and PET scans can spot signs of leukaemia.
The treatment you get depends on the type of leukaemia you have, how far it’s spread, and how healthy you are. The main options are:
- Chemotherapy. Chemotherapy is the major form of treatment for leukemia. This drug treatment uses chemicals to kill leukemia cells.
Depending on the type of leukemia you have, you may receive a single drug or a combination of drugs. These drugs may come in a pill form, or they may be injected directly into a vein.
- Targeted therapy. Targeted drug treatments focus on specific abnormalities present within cancer cells. By blocking these abnormalities, targeted drug treatments can cause cancer cells to die. Your leukemia cells will be tested to see if targeted therapy may be helpful for you.
- Radiation therapy. Radiation therapy uses X-rays or other high-energy beams to damage leukemia cells and stop their growth. During radiation therapy, you lie on a table while a large machine moves around you, directing the radiation to precise points on your body.
You may receive radiation in one specific area of your body where there is a collection of leukemia cells, or you may receive radiation over your whole body. Radiation therapy may be used to prepare for a bone marrow transplant.
- Bone marrow transplant. A bone marrow transplant, also called a stem cell transplant, helps reestablish healthy stem cells by replacing unhealthy bone marrow with leukemia-free stem cells that will regenerate healthy bone marrow.
Prior to a bone marrow transplant, you receive very high doses of chemotherapy or radiation therapy to destroy your leukemia-producing bone marrow. Then you receive an infusion of blood-forming stem cells that help rebuild your bone marrow.
You may receive stem cells from a donor or you may be able to use your own stem cells.
- Immunotherapy. Immunotherapy uses your immune system to fight cancer. Your body’s disease-fighting immune system may not attack your cancer because the cancer cells produce proteins that help them hide from the immune system cells. Immunotherapy works by interfering with that process.
- Engineering immune cells to fight leukemia. A specialized treatment called chimeric antigen receptor (CAR)-T cell therapy takes your body’s germ-fighting T cells, engineers them to fight cancer and infuses them back into your body. CAR-T cell therapy might be an option for certain types of leukemia.
- Clinical trials. Clinical trials are experiments to test new cancer treatments and new ways of using existing treatments. While clinical trials give you or your child a chance to try the latest cancer treatment, treatment benefits and risks may be uncertain. Discuss the benefits and risks of clinical trials with your doctor.