Written by epgonline.org - Last updated 29 May 2018
Leukaemia constitutes a range of cancers, typically originating in the bone marrow, and resulting in overproduction of abnormal blood cells. It is a common condition, with World Health Organization estimates of 352,000 new cases and 265,000 deaths in 2012. There is a male predominance, with estimates of a 1% lifetime risk in females, and 1.5% in males. Although the overall disease burden is higher with increasing age, different leukaemia types have incidence ‘peaks’ at variable ages; for example, acute lymphocytic leukaemia is more common in childhood, while acute myelogenous leukaemia is most common in young adults.
The exact pathological causes for most leukaemia types are unknown, although a causative mutation may arise as a result of an ionising substance. Pathologically, a blood cell progenitor undergoes a mutation resulting in abnormal proliferation, clonal expansion and decreased response to apoptosis signals. This may be myelogenous (erythrocyte progenitors), or lymphocytic (B-cells – progenitors of leukocytes). The other key distinction is the differentiation between acute and chronic disease – acute disease results in a rapid rise in immature blood cells, the bone marrow is largely taken over, leaving minimal resources to provide functional cells. Chronic disease results in an overproduction of relatively mature but still abnormal cells. Other rarer leukaemia types are also covered in this section, including: hairy cell, T-cell prolymphocytic, large cell, granular lymphocytic and adult T-cell. Chronic lymphocytic leukaemia is covered in greater detail in our knowledge centre.
Clinical presentation is often with symptoms resulting from low platelets – increased bruising or bleeding. As other blood elements are decreased, recurrent infections may result from decreased functional leukocytes, or symptoms of anaemia may begin to manifest. Other non-specific symptoms including nausea, chills and flu-like symptoms may also be presenting features. Diagnosis is usually made by a combination of repeated full blood count tests and bone marrow biopsies.
Treatment aims vary depending on the type of leukaemia, and chronic disease is often approached with the aim of managing the disease rather than curing it. Treatment options include chemotherapeutic agents, steroids, immunotherapy, targeted agents and the use of allogenic bone marrow transplantation. Prognosis is variable and dependant on the type of leukaemia and age at diagnosis.