Leukemia has well-defined predisposing factors. Different etiologies cause cumulative genetic mutations in normal hematopoietic stem/progenitor cells through different mechanisms, ultimately altering cell biological behavior.
The following are common etiologies of leukemogenesis:
(i) Viruses
The viral etiology of human leukemia has been studied for decades, but so far only two rare types of leukemia have been associated with viruses: human T-cell-loving virus type I (HTLV-I) is the causative agent of adult T-cell lymphoma/leukemia; and EBV is thought to be associated with the development of Burkitt’s lymphoma/leukemia.
(ii) Radiation
Ionizing radiation is leukemogenic and its effects are related to the magnitude of the radiation dose, the site of radiation, and age.
The incidence of leukemia among survivors of the 1945 atomic bombings of Hiroshima and Nagasaki in Japan was tens of times higher than among unirradiated people; radiotherapy can also cause leukemia, and the incidence of leukemia after radiotherapy in patients with ankylosing spondylitis is more than ten times higher than in the general population, and is dose-related; occupational long-term exposure can also cause leukemia, and the incidence of leukemia was relatively high among medical personnel engaged in radiological diagnosis and treatment in the past, but with The incidence of leukemia in medical personnel engaged in diagnostic and therapeutic radiology used to be relatively high, but with improved protection measures, the incidence has been largely consistent with the general population.
(iii) Chemical agents
The leukemogenic effect of benzene is relatively certain. One study found that the risk of leukemia was 10 to 11 times greater in workers with long-term exposure to vinyl chloride than in controls, and four times greater in those with long-term exposure to lead.
The chemotherapeutic drugs alkylating agents and topoisomerase II inhibitors can cause secondary leukemia is also more certain; most secondary leukemia occurs after long-term alkylating agent therapy for pre-existing lymphatic system malignancies and malignancies prone to immunodeficiency, and secondary leukemia is also prone to occur after chemotherapy for breast, ovarian, and lung cancers; in recent years, cases of leukemia caused by etanercept have been reported in China, and the drug is used to treat psoriasis, which is an extremely potent chromosomal aberration-causing substance. Other drugs that have been associated with the development of leukemia include chloramphenicol and protamine.
(iv) Lifestyle
Smoking is not associated with leukemogenesis, but one study showed that smoking increased the incidence of t(8;21) acute myeloid leukemia (AML); certain foods have topoisomerase II inhibitory effects and may increase the incidence of AML in infants when consumed during pregnancy; and alcohol consumption during pregnancy may also increase the incidence of AML in infants after birth.
(v) Genetic factors
The risk of acute leukemia in first-degree relatives of patients with leukemia is 3 times higher than in the general population. There is no definitive explanation for the occurrence of family leukemia, which may be related to genetic qualities or to exposure to the same leukemogenic factors in a shared living environment.