Leukemia (Blood Cancer) is a cancer of the blood or bone marrow characterized by an abnormal proliferation of blood cells, usually white blood cells (leukocytes). It is part of the broad group of diseases called hematological neoplasms.
No one knows what causes leukemia. Researchers have strong suspicions about four possible causes. They are radiation, chemicals, viruses, and genetic factors. Leukemia, like other cancers, result from somatic mutations in the DNA which activate oncogenes or deactivate tumor suppressor genes, and disrupt the regulation of cell death, differentiation or division. These mutations may occur spontaneously or as a result of exposure to radiation or carcinogenic substances and are likely to be influenced by genetic factors. Cohort and case control studies have linked exposure to petrochemicals, such as benzene, and hair dyes to the development of leukemia.