Leukemia is a cancer of the blood or bone marrow, which produces blood cells. Leukemia happens when there is a problem with blood cell production. It usually affects the leukocytes, or white blood cells.
The National Cancer Institute estimates that
There are different types of leukemia, and the outlook depends on the type. Acute leukemia develops quickly and worsens rapidly, but chronic leukemia gets worse over time.
In this article, we provide an overview of leukemia, causes, treatment, type, and symptoms.
Usually, healthy blood cells die after a while, and new cells develop in the bone marrow and replace them.
In leukemia, the blood cells
As the bone marrow produces more cancer cells, they begin to overcrowd the blood, preventing the healthy white blood cells from growing and functioning normally. This also affects the platelets and red blood cells.
Eventually, the cancerous cells outnumber healthy cells in the blood.
Experts often do not know why leukemia happens, but environmental and genetic factors likely
While genetic features may not cause leukemia, they may make it more likely to appear in certain conditions, for example, after exposure to some chemicals or infections.
Risk factors will depend on the type. Some risk factors are avoidable, but others are not.
Scientists have found links between leukemia and various factors, although more research is needed to confirm most of them.
- a history of certain infections, such as the Epstein-Barr virus
- exposure to ionizing radiation, for example, during radiation therapy for a previous cancer, background radiation, or being near a site where people were testing nuclear weapons
- having a high or low birth weight
- being male, as rates are higher among males
- exposure to pesticides and air pollution
- having parents who smoke tobacco
- having a cesarean delivery before labor started
- having a genetic condition
such asDown syndrome or Klinefelter syndrome
- exposure to benzene
- a previous history of chemotherapy
- having already had one type of blood cancer
Doctors classify the different types of leukemia according to:
- the type of blood cell they start in
- whether they are acute (grow quickly) or chronic (grow slowly)
- if they occur in a child or an adult
Chronic and acute leukemias
In acute leukemia, developing cells multiply quickly and collect in the marrow and blood. A blood test will show that more than
Chronic leukemia progresses more slowly. It allows for the production of more mature, useful cells. In a blood test, fewer than 20% of cells are blasts.
Lymphocytic and myelogenous leukemias
Lymphocytic leukemia occurs if cancerous changes affect the type of bone marrow that makes lymphocytes. A lymphocyte is a white blood cell that plays a role in the immune system.
Myelogenous leukemia happens when the changes affect bone marrow cells that produce blood cells rather than the blood cells themselves.
There are several types of leukemia. They include:
Acute lymphocytic leukemia
Chronic lymphocytic leukemia
Chronic lymphocytic leukemia (CLL) mostly affects people over
Acute myelogenous leukemia
Chronic myeloid leukemia
Chronic myelogenous leukemia (CML) accounts for around
Hairy cell leukemia
Hairy cell leukemia (HCL) is a rare type of leukemia that mostly affects adults in middle age and older. In the U.S., there are around 1,000 new cases each year. It is chronic and tends to be slow-growing.
It gets its name because, under the microscope, the cancer cells have fine, hair-like strands.
Treatment options will depend on:
- the type of leukemia
- the person’s age
- their overall health
- watchful waiting for slow-growing leukemias, such as CLL and HCL
- radiation therapy
- targeted therapy
- bone marrow transplant
- surgery to remove the spleen
- stem cell transplant with chemotherapy
A cancer care team will tailor this to suit the type of leukemia. Treatment that starts early is more likely to be effective.
Symptoms of leukemia vary according to the type.
They include the following:
Easy bruising or bleeding
Leukemia affects the platelets in the body, making it harder for blood to clot.
A person may:
- bruise easily and often
- have small wounds that bleed a lot and heal slowly
- have nosebleeds or bleeding from the gums
- develop petechiae — tiny red spots on the skin
- have purpura — purple areas on the skin
As fewer effective red blood cells become available, anemia may develop. This happens when there is not enough hemoglobin in the blood.
Symptoms of anemia
Other possible symptoms
The symptoms of leukemia can all occur with other conditions. Anyone who has concerns about symptoms should seek medical advice. A doctor will carry out tests to identify the cause.
A doctor will most likely:
- carry out a physical examination
- ask about personal and family medical history
- check for signs of anemia
- feel for an enlarged liver or spleen
take bloodfor testing in a laboratory
If the doctor suspects leukemia, they may suggest a bone marrow biopsy. A surgeon extracts bone marrow from the center of a bone, usually from the hip, using a long, fine needle.
This can show if leukemia is present and, if so, which type.
People often ask the following questions about leukemia.
How do you get leukemia?
Genetic and environmental factors may play a role. Depending on the type of leukemia, there is
Is leukemia a serious cancer?
All cancer is serious and needs medical attention. There are different types of leukemia, and some progress more quickly than others. Without treatment, leukemia can be fatal, but medical progress means a person is more likely to survive with leukemia than in the past.
What is the survival rate for leukemia?
Overall, a person with leukemia has a
The outlook for people with leukemia depends on the type. The person’s age and overall health will also play a role.
A doctor cannot predict how long an individual is likely to live with leukemia, but statistics from past studies can show some trends.
Treatment can lead to remission, when all the signs of leukemia have disappeared. A person will still need monitoring and tests for some time to ensure leukemia does not return.
Leukemia is a type of cancer that affects the blood and bone marrow. There are various types, and some can affect children.
Experts do not know exactly why leukemia happens, but genetic factors and exposure to toxins, such as pesticides, may play a role.
The main treatment option is chemotherapy, but other approaches are available, depending on the type of leukemia.
The survival rates for leukemia have