Leukemia is caused by genetic mutations in the DNA of blood-forming cells, most often white blood cells, which lead to uncontrolled growth and division of these abnormal cells. These mutations disrupt normal cell functions such as growth, differentiation, and death, causing an accumulation of abnormal cells in the bone marrow and blood that crowd out healthy cells
. The exact cause of these DNA mutations is unknown, but leukemia is believed to result from a combination of genetic predispositions and environmental factors
. Known risk factors include:
- Exposure to intense or high levels of radiation, such as from nuclear accidents or radiation therapy
- Exposure to certain chemicals, particularly benzene and formaldehyde, often found in industrial settings
- Infection with certain viruses, such as the Human T-cell leukemia virus (HTLV-1), which is linked to adult T-cell leukemia
- Genetic conditions and chromosomal abnormalities, such as the Philadelphia chromosome in chronic myeloid leukemia (CML), Down syndrome, Fanconi anemia, and other inherited syndromes
- Previous cancer treatments, including chemotherapy and radiation therapy, which can increase leukemia risk
- Lifestyle factors like smoking, which is associated with a higher risk of acute myeloid leukemia (AML)
Additionally, some familial or inherited genetic predispositions may increase leukemia risk, although most leukemias are not directly hereditary
. In summary, leukemia arises from mutations in blood cell DNA triggered by a complex interplay of genetic and environmental factors, including radiation, chemical exposures, viral infections, genetic syndromes, and prior cancer treatments
