Leukaemia: Definition of Leukaemia
Leukaemia is a group of heterogenous neoplastic disorder of white blood cells. It is a neoplastic clonal disorder of the bone marrow. Because it is a type of cancer of the blood, bone marrow and lymphoid system they are known as the haematological neoplasms. Leukaemia is an uncontrolled production of white blood cells caused by cancerous mutation of a myelogenous or lymphogenous cell. Cancer is a group of diseases characterised by an abnormal and uncontrolled growth of cells in body organs or tissues.
Leukaemia is characterised by the accumulation of malignant or immature white blood cells called “blasts” in the peripheral blood or bone marrow. The white blood cells crowd out other blood cells element such as platelets and red blood cells. The elevated white blood cells are immature and malfuntional. The cancerous cells made in the bone marrow spill into the blood stream causing adverse effects. These adverse effects include:
- Bone marrow failure which result in anaemia, leukopenia and thrombocytopenia.
- Infilteration of organs like the liver, spleen, brain, lymph nodes, meninges, testis or skin.
Leukaemia is diverse in origin, clinical manifestation. And prognostic outcomes. It has no age discrepancy, that is more common in adults than in children and in caucassians than Africans.
There are four main types of leukaemia classified based on their cell lineage implicated (myeloid and lymphoid) and clinical course (Acute and chronic) giving rise to Acute myeloid leukaemia, chronic lymphoid leukaemia.
Because many types of leukaemia are asymptomatic at onset, leukaemia may be diagnosed incidently based on; full blood counts (especially white blood cells, red blood cells and platelet counts), bone marrow examination (confirmatory test), lymph node biopsy (in the early stage or if is in remission stage), physical examination (swollen gum, pale colouration, splenomegally, hepatomegaly, enlarged lymph nodes, etc), cytochemistry (to determine the degree of liver and kidney damage),chemotherapy, cytogenetic and immunological analysis.
Important prognostic factors in leukaemia include: the age of the patient, the type of leukaemia and the chromosomal abnormalities found in leukaemia cells and bone marrow.
While the reported incidence of leukaemia has not changed much since 1950s, most forms of leukaemia are treated with pharmaceutical medications, typically combined into a multi-drug chemotherapy regimen. Some are treated with radiation therapy. In some cases, a bone marrow transplant is useful. The drug known as imatinib (Gleevec) has been used in the management of chronic myeloid leukaemia. Other important drugs are nilotinib, bosutinib, dasatinib and synribo. Treatment via gene therapy is currently in progress.