Leukemia

For the journal, see Leukemia (journal). For animal diseases, see Leucosis.

Leukemia
Other namesLeukaemia
A Wright's stained bone marrow aspirate smear from a person with B-cell acute lymphoblastic leukemia
Pronunciation
SpecialtyHematology and oncology
SymptomsBleeding, bruising, fatigue, fever, increased risk of infections[2]
Usual onsetAll ages,[3] most common in 60s and 70s.[4] It is the most common malignant cancer in children, but the cure rates are also higher for them.
CausesInherited and environmental factors[5]
Risk factorsSmoking, family history, ionizing radiation, some chemicals such as trichloroethylene, prior chemotherapy, Down syndrome.[3][5]
Diagnostic methodBlood tests, bone marrow biopsy[2]
TreatmentChemotherapy, radiation therapy, targeted therapy, bone marrow transplant, supportive care[3][6]
PrognosisFive-year survival rate 67% (U.S.)[4]
Frequency2.3 million (2015)[7]
Deaths353,500 (2015)[8]

Leukemia (also spelled leukaemia; pronounced /luːˈkiːmiːə/[1] loo-KEE-mee-ə) is a group of blood cancers that usually begin in the bone marrow and produce high numbers of abnormal blood cells.[9] These blood cells are not fully developed and are called blasts or leukemia cells.[2] Symptoms may include bleeding and bruising, bone pain, fatigue, fever, and an increased risk of infections.[2] These symptoms occur due to a lack of normal blood cells.[2] Diagnosis is typically made by blood tests or bone marrow biopsy.[2]

The exact cause of leukemia is unknown.[5] A combination of genetic factors and environmental (non-inherited) factors are believed to play a role.[5] Risk factors include smoking, ionizing radiation, petrochemicals (such as benzene), prior chemotherapy, and Down syndrome.[5][3] People with a family history of leukemia are also at higher risk.[3] There are four main types of leukemia—acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL) and chronic myeloid leukemia (CML)—and a number of less common types.[3][10] Leukemias and lymphomas both belong to a broader group of tumors that affect the blood, bone marrow, and lymphoid system, known as tumors of the hematopoietic and lymphoid tissues.[11][12]

Treatment may involve some combination of chemotherapy, radiation therapy, targeted therapy, and bone marrow transplant, with supportive and palliative care provided as needed.[3][6] Certain types of leukemia may be managed with watchful waiting.[3] The success of treatment depends on the type of leukemia and the age of the person. Outcomes have improved in the developed world.[10] Five-year survival rate was 67% in the United States in the period from 2014 to 2020.[4] In children under 15 in first-world countries, the five-year survival rate is greater than 60% or even 90%, depending on the type of leukemia.[13] In children who are cancer-free five years after diagnosis of acute leukemia, the cancer is unlikely to return.[13]

In 2015, leukemia was present in 2.3 million people worldwide and caused 353,500 deaths.[7][8] In 2012, it had newly developed in 352,000 people.[10] It is the most common type of cancer in children, with three-quarters of leukemia cases in children being the acute lymphoblastic type.[3] However, over 90% of all leukemias are diagnosed in adults, CLL and AML being most common.[3][14] It occurs more commonly in the developed world.[10]

  1. ^ a b "Leukemia". Merriam-Webster. 30 May 2023.
  2. ^ a b c d e f "What You lNeed To Know About Leukemia". National Cancer Institute. 23 December 2013. Archived from the original on 6 July 2014. Retrieved 18 June 2014.
  3. ^ a b c d e f g h i j "A Snapshot of Leukemia". NCI. Archived from the original on 4 July 2014. Retrieved 18 June 2014.
  4. ^ a b c "SEER Stat Fact Sheets: Leukemia". National Cancer Institute. 2024. Updated as required.
  5. ^ a b c d e Hutter JJ (June 2010). "Childhood leukemia". Pediatrics in Review. 31 (6): 234–241. doi:10.1542/pir.31-6-234. PMID 20516235. S2CID 207170780.
  6. ^ a b Cordo' V, van der Zwet JC, Canté-Barrett K, Pieters R, Meijerink JP (January 2021). "T-cell Acute Lymphoblastic Leukemia: A Roadmap to Targeted Therapies". Blood Cancer Discovery. 2 (1): 19–31. doi:10.1158/2643-3230.BCD-20-0093. PMC 8447273. PMID 34661151.
  7. ^ a b Vos T, Allen C, Arora M, Barber RM, Bhutta ZA, Brown A, et al. (October 2016). "Global, regional, and national incidence, prevalence, and years lived with disability for 310 diseases and injuries, 1990–2015: a systematic analysis for the Global Burden of Disease Study 2015". Lancet. 388 (10053): 1545–1602. doi:10.1016/S0140-6736(16)31678-6. PMC 5055577. PMID 27733282.
  8. ^ a b Wang H, Naghavi M, Allen C, Barber RM, Bhutta ZA, Carter A, et al. (October 2016). "Global, regional, and national life expectancy, all-cause mortality, and cause-specific mortality for 249 causes of death, 1980–2015: a systematic analysis for the Global Burden of Disease Study 2015". Lancet. 388 (10053): 1459–1544. doi:10.1016/s0140-6736(16)31012-1. PMC 5388903. PMID 27733281.
  9. ^ "Leukemia". NCI. 1 January 1980. Archived from the original on 27 May 2014. Retrieved 13 June 2014. Cancer that starts in blood-forming tissue, such as the bone marrow, and causes large numbers of abnormal blood cells
  10. ^ a b c d "5.13 Haematopoietic and lymphoid malignancies". World Cancer Report 2014. World Health Organization. 2014. pp. 482–494. ISBN 978-92-832-0429-9.
  11. ^ Vardiman JW, Thiele J, Arber DA, Brunning RD, Borowitz MJ, Porwit A, et al. (July 2009). "The 2008 revision of the World Health Organization (WHO) classification of myeloid neoplasms and acute leukemia: rationale and important changes". Blood. 114 (5): 937–951. doi:10.1182/blood-2009-03-209262. PMID 19357394. S2CID 3101472.
  12. ^ Baba AI, Câtoi C, eds. (2007). Comparative oncology. Bucharest: The Publishing House of the Romanian Academy. p. Chapter 17. ISBN 978-973-27-1457-7. Archived from the original on 10 September 2017.
  13. ^ a b American Cancer Society (2 March 2014). "Survival rates for childhood leukemia". Archived from the original on 14 July 2014.
  14. ^ "Chronic Lymphocytic Leukemia (CLL) — Hematology and Oncology". MSD Manual Professional Edition. Retrieved 1 February 2020.