Causes of acute lymphoblastic leukemia
The majority of studies of acute lymphoblastic leukemia are based on the children population, and investigators have found that many different factors are influencing this type of blood cancer. It is usually a two-step process that includes genetic susceptibility or genetic mutations, and subsequent exposure of the patient to certain infections that trigger exaggerated replication of lymphocyte precursor cells.
In children, acute lymphoblastic leukemia starts in the uterine life, when genes become defective in the bone marrow. This is called a pre-leukemic clone, and it causes leukemia when these genes become activated, which only happens in 1% of the population with a pre-leukemic clone.
With a pre-leukemic clone, the body usually activates leukemia in children with a defective immune response, usually when newborns are not properly exposed to infections during their first weeks. Thus, it is not uncommon to see leukemia in families that are extremely devoted to hygienic measures and cleaning practices.
In adults, ALL does not have identifiable risk factors, and it is not as common as acute myeloid leukemia. It is suspected that certain types of radiations may trigger ALL in adults, as it happened in survivors of the atomic bomb in Hiroshima. Other factors that may be associated with secondary leukemia are other types of cancer, including ovarian cancer, lung cancer, and Hodgkin lymphoma.