What is leukemia?
Leukemia is a cancer of the blood-forming tissues, including bone marrow and lymphatic system. It arises when white blood cells grow abnormally and crowd out healthy blood cells. These malignant cells can spread beyond the bone marrow to organs such as the liver, spleen, lymph nodes, and skin.
In 2024, over 62,000 new cases are expected in the U.S., making it the 10th most common cancer. The five-year survival rate for adults overall is about 67%.
Types of leukemia
- Acute lymphocytic leukemia (ALL): rapid-growing cancer of lymphoid cells, most common in children, often spreads to the brain, spinal cord, liver, spleen, and lymph nodes.
- Acute myeloid leukemia (AML): fast-growing malignancy of myeloid lineage affecting red cells, white cells, and platelets; most common acute leukemia in adults.
- Chronic lymphocytic leukemia (CLL): slow-growing cancer of mature lymphocytes, typically found in older adults and may be asymptomatic for years.
- Chronic myeloid leukemia (CML): cancer of myeloid cells with slower progression; characterized by the Philadelphia chromosome and often affects adults.
- Other types include hairy cell leukemia, large granular lymphocytic (LGL) leukemia, and prolymphocytic leukemia (PLL).
What causes leukemia?
- Genetic mutations in blood-cell DNA, sometimes inherited
- Chemical exposures such as benzene
- Prior chemotherapy or radiation therapy
- Genetic syndromes like Down syndrome
- Family history of blood cancers
- Smoking, especially linked to AML
- Certain autoimmune disorders
Symptoms of leukemia
- Fatigue, weakness, and pallor due to anemia
- Frequent or severe infections from low healthy white cell counts
- Unexplained fevers, chills, and night sweats
- Easy bruising, bleeding gums, and petechiae
- Swollen lymph nodes in neck, armpits, or groin
- Unintended weight loss
- Bone or joint pain, enlarged spleen or liver
- Shortness of breath on exertion
How is leukemia diagnosed?
- Medical history and physical exam to check lymph nodes, spleen, and liver
- Complete blood count (CBC) and blood smear to detect abnormal cells
- Bone marrow biopsy to confirm type and extent
- Genetic and molecular tests on blood or marrow cells
- Imaging studies such as X-ray, CT, MRI, or ultrasound
- Lumbar puncture to assess central nervous system involvement when indicated
How is leukemia treated?
- Chemotherapy to kill or slow cancer cells
- Radiation therapy targeted to affected areas
- Targeted therapy against specific genetic features
- Immunotherapy, including monoclonal antibodies and CAR T-cell therapy
- Stem cell transplant to replace diseased marrow
- Supportive care with transfusions, antibiotics, and growth factors
- Clinical trials for access to emerging treatments
Sources
- The Leukemia & Lymphoma Society. “Leukemia.” Accessed May 24, 2024.
- National Cancer Institute. “Leukemia.” Accessed May 24, 2024.
- MD Anderson Cancer Center. “Leukemia.” Accessed May 24, 2024.
- American Cancer Society. “Leukemia.” Accessed May 24, 2024.