Leukemia /luːkiːmiːɑː/ (American English) or leukaemia (British English) is a group of cancers that usually begins in the bone marrow and results in abnormal white blood cells in high numbers.[1]These white blood cells are not fully developed and are called blastsor leukemia cells.[2] Symptoms may include: bleeding and bruisingproblems, feeling very tired, and an increased risk of infections.[2]These occur due to a lack of normal blood cells.[2]
’’’白血病’’’（{{lang-en-am|leukaemia}}，{{lang-en-gb|leukaemia}}，{{IPAc-en|l|uː|ˈ|k|iː|m|iː|ə}}[0]）是一群[[癌症]]種類的統稱，通常發病於[[骨髓]]，造成不正常的[[白血球]]大量增生[1]。這些異常增加的白血球都尚未發育完成，稱之為[[前體細胞|芽細胞]]或白血病細胞[2]。症狀可能包含：出血與[[淤斑]]、[[疲倦]]以及感染風險增加[2]。這些症狀會因缺乏正常[[血球]]而發生[2]。
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While the exact cause of leukemia is unknown; a combination of environmental and genetic factors are believed to play a role.[3] Risk factors include: smoking, ionizing radiation, some chemicals including benzene, prior chemotherapy, and Down syndrome.[3][4]Those with a family history are also at higher risk.[4] Leukemia including four main cancers: acute lymphoblastic leukemia (ALL),acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL) and chronic myeloid leukemia (CML) as well as a number of less common cancers.[5][4] It is part of a broader group tumors which affect the blood, bone marrow, and lymphoid system, known astumors of the hematopoietic and lymphoid tissues.[6] Diagnosis is typically by blood tests or bone marrow biopsy.[2]
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白血病發生的真正原因尚未知曉；目前相信環境與遺傳因素都扮演了重要角色[3]。風險因子包含：{{link-en|吸菸|Smoking}}、[[游離輻射]]、部分化學物質如[[苯]]、過去接受過化療、[[唐氏綜合症]][3][4]、家族史有白血病[4]。白血病可被分為：[[急性淋巴性白血病]]、[[急性骨髓性白血病]]、{{link-en|B細胞慢性淋巴性白血病|B-cell chronic lymphocytic leukemia}}與[[慢性粒細胞性白血病|慢性骨髓性白血病]]這四大類型，以及其他較不常見的種類[4][5]。白血病屬於影響血液、骨髓與[[淋巴系統]]的[[腫瘤]]當中的一種，此大類疾病被稱為{{link-en|造血和淋巴組織腫瘤|Tumors of the hematopoietic and lymphoid tissues}}[6]。白血病的診斷主要靠[[血液檢查]]與{{link-en|骨髓檢查|Bone marrow examination}}[2]。
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Treatment may involve some combination of chemotherapy,radiation therapy, targeted therapy, and bone marrow transplant. Certain types of leukemia may be managed with watchful waiting.[4]Outcomes have improved in the developed world.[5] The averagefive year survival rate is 57% in the United States.[7] In children five year survival is greater than 60 to 85% depending on the type of leukemia.[8] In those with acute disease who are cancer free after five years it is unlikely for the cancer to return.[8] Blood or platelet transfusions as well as pain management may be required.[2] Palliative care may be useful with or without further efforts to control the disease.[9]
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白血病的治療方式，包括[[化學療法]]、[[放射線療法]]、[[靶向治療|標靶治療]]與[[骨髓移植]]。某些類型的白血病會採用所謂「{{link-en|觀察等待|Watchful waiting}}」的策略<ref name=NCISnap/>。預後方面，在已開發國家中較以前有明顯進步，以美國為例，其{{link-en|五年存活率|Five-year survival rate}}在2011年的統計數據為57%<ref name=SEER>{{cite web| url = http://seer.cancer.gov/statfacts/html/leuks.html#incidence-mortality| title = SEER Stat Fact Sheets: Leukemia| year = 2011| publisher = National Cancer Institute}}</ref>。兒童的五年存活率一般而言比成人高，依據白血病的類型不同，大約在60到85%之間<ref name=ACS2014/>。值得一提的是，急性白血病的病患若接受治療痊癒且5年內沒有復發的話，之後終身復發的機率相當低<ref name=ACS2014>{{cite web|author1=American Cancer Society|title=Survival rates for childhood leukemia|url=http://www.cancer.org/cancer/leukemiainchildren/overviewguide/childhood-leukemia-overview-survival-rates|date=02/03/2014}}</ref>。另外，白血病的治療有可能需要配合[[輸血]]或{{link-en|輸血小板|Plateletpheresis}}及{{link-en|疼痛管理|Pain management}}<ref name=NCIBook2013/>。[[臨終關懷|安寧緩和治療]]不論有沒有進一步治療以控制，都可能有幫助<ref>{{cite book|last1=Hesdorffer|first1=Candis Morrison, Charles S. [i.e. L.?]|title=Johns Hopkins patients’ guide to leukemia|date=2011|publisher=Jones and Bartlett Learning|location=Sudbury, Mass.|isbn=9781449618896|page=109|url=http://books.google.ca/books?id=ScY6aFzPUtsC&pg=PT109}}</ref>。
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In 2012 leukemia developed in 352,000 people and cause 265,000 deaths.[5] It is the most common type of cancer in children with three quarters of cases being ALL.[4] About 90% of all leukemias are; however, diagnosed in adults with AML and CCL being most common.[4] It occurs more commonly in the developed world.[5] In the United States around $5.4 billion is spent on treatment a year.[4] The name comes from Ancient Greek λευκόςleukos "white", and αἷμα haima "blood"[10]
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2012年，共有35.2萬位新的白血病病患，並造成26.5萬人死亡<ref name=WCR2014>{{cite book|title=World Cancer Report 2014.|date=2014|publisher=World Health Organization|isbn=9283204298|pages=Chapter 5.13}}</ref>。白血病是最常見的兒童癌症，其中3/4的病例是急性淋巴性白血病<ref name=NCISnap/>。然而，90%的成人病患當中，急性骨髓性白血病與B細胞慢性淋巴性白血病是最常見被確診的種類<ref name=NCISnap/>。白血病最常在[[已開發國家]]出現<ref name=WCR2014/> 。在美國，白血病一年的醫療支出為54億美元<ref name=NCISnap/>。白血病的英文名稱來自於[[古希臘語]]，{{lang|grc|λευκός}}（{{lang|en|leukos}}，白色）與{{lang|grc|αἷμα}}（{{lang|en|haima}}，血液）的組合<ref>{{cite book |chapter=Leukemia |title=Mosby’s Medical, Nursing &Allied Health Dictionary |edition=Fourth |publisher=Mosby-YearBook |year=1994 |page=903 }}</ref>。