Understanding CML
Haematological Malignancy and Leukaemia
Haematological malignancies are defined as neoplastic growths or cancers of blood cells. Malignant transformation in haematological malignancies, as in all cancers, occurs by a multistep process by which a single cell acquires a growth or survival advantage. This advantage leads to the uncontrolled growth of this cell and its progeny, resulting in the expansion of an identical, or clonal, population of cells. When this process of malignant transformation and uncontrolled growth occurs in any of the leukocyte cell lineages, the cancer that results is called leukaemia.
Types of Leukaemia
Most common forms of leukaemia are classified according to cell lineage (myeloid or lymphoid) and degree of terminal cellular differentiation, which relates to the clinical course of the disease. Acute leukaemias arise from neoplastic transformation of a primitive progenitor cell limited in its capacity for further maturation. Acute forms of the disease-acute myeloid leukaemia (AML) and acute lymphoblastic leukaemia (ALL)-evolve rapidly and require prompt intervention. Chronic leukaemia arises from neoplastic transformation of a primitive progenitor cell that retains the ability to further differentiate and mature. Chronic forms of the disease-CML and chronic lymphoblastic leukaemia (CLL)-generally progress in an indolent manner, consistent with the slower proliferative capacity of more mature cells. CML is a myeloproliferative disease characterised by the presence of the Philadelphia chromosome (Ph) or the BCR-ABL fusion oncogene.1
References:
1. Vardiman JW, Harris NL, Brunning RD. The World Health Organization (WHO) classification of the myeloid neoplasms. Blood. 2002;100:2292-2302.