Leukemia is a term for cancers of the blood cells. It starts in blood-forming tissue such as the bone marrow, which makes the cells that become white blood cells, red blood cells and platelets. Each has its own job: white blood cells fight infection, red blood cells carry oxygen from the lungs to the tissues and organs, and platelets help form clots to stop bleeding.
In leukemia, the bone marrow makes large numbers of abnormal cells, most often white blood cells. They build up in the marrow and the blood, crowd out healthy blood cells, and make it hard for the blood and cells to do their work.
Types
The type depends on which blood cell becomes cancerous — lymphocytes, a type of white blood cell, or myeloid cells, immature cells that become white blood cells, red blood cells or platelets — and on how fast it grows. Acute leukemia grows quickly and usually worsens fast without treatment; chronic leukemia grows slowly and worsens over a longer time.
| Type | Who it usually affects |
|---|---|
| Acute lymphocytic leukemia (ALL) | the most common cancer in children; can also affect adults |
| Acute myeloid leukemia (AML) | more common in older adults; can also affect children |
| Chronic lymphocytic leukemia (CLL) | one of the most common leukemias in adults, often during or after middle age |
| Chronic myeloid leukemia (CML) | usually adults, during or after middle age |
Causes and risk
Leukemia happens when the genetic material (DNA) in bone marrow cells changes, but the cause of those changes is unknown. Different factors raise the risk of different types. Overall, the risk rises with age, and leukemia is most common after 60.
Symptoms
Symptoms can include:
- feeling tired;
- fever or night sweats;
- bruising or bleeding easily;
- weight loss or loss of appetite; and
- petechiae, tiny red dots under the skin caused by bleeding.
Other symptoms vary by type, and chronic leukemia may cause none at first.
Diagnosis
A provider may use a physical exam, a medical history, blood tests such as a complete blood count (CBC), and bone marrow tests — aspiration or biopsy, both of which remove a sample of marrow and bone for laboratory testing. Genetic tests look for changes in genes and chromosomes. After diagnosis, imaging tests and a lumbar puncture, which collects and tests cerebrospinal fluid, may show whether the cancer has spread.
Treatment
Treatment depends on the type and severity of leukemia, the patient's age and overall health, and other factors. Options can include chemotherapy, radiation therapy, chemotherapy with a stem cell transplant, and targeted therapy, which uses drugs or other substances that attack specific cancer cells while doing less harm to normal cells.
Sources
- MedlinePlus, U.S. National Library of Medicine, "Leukemia" (summary from the National Cancer Institute): https://medlineplus.gov/leukemia.html
Licence: CC0 1.0 (public domain) · Adapted from medlineplus.gov
1
0
0
0
Comments
