Leukemia is a clonal disease that is caused by mutations and altered expression of genes leading to a malignant transformation of hematopoietic precursors. In most cases, a specific cause of these genetic changes can not be identified. However, we do know that a number of factors could be responsible for causing these genetic changes including:
- Environmental exposures such as exposures to radiation (especially seen in acute and chronic myeloid leukemias)
- Chemical and drug exposures such as benzene and organic solvents
- Immunosuppression such as in organ transplant patients
- Pre-existing genetic abnormalities as in Down Syndrome, Fanconi's Anemia, etc.
- Certain viruses (more often seen in chronic leukemias or lymphomas)
- Treatment of previous cancerous conditions with chemotherapy and/or radiation
