A risk factor is anything that may increase your risk for a disease. Risk factors may be different for the different types of leukemia:
- Radiation: Exposure to very high levels of radiation can lead to acute myeloid leukemia, chronic myeloid leukemia, or acute lymphocytic leukemia.
- CT scans: Recent research suggests a possible link between CT scans in childhood and leukemia later in life, but more research is needed.
- Smoking: Smoking cigarettes increases the risk of acute myeloid leukemia.
- Benzene: Exposure to benzene in the workplace can cause acute myeloid leukemia. It may also cause chronic myeloid leukemia or acute lymphocytic leukemia. Benzene is used widely in the chemical industry. It's also found in cigarette smoke and gasoline.
- Chemotherapy: Cancer patients treated with certain types of cancer-fighting drugs sometimes develop acute myeloid leukemia or acute lymphocytic leukemia later on. For example, being treated with drugs known as alkylating agents or topoisomerase inhibitors has been linked to a small chance of developing acute leukemia.
- Down syndrome and certain other inherited diseases: Down syndrome and certain other inherited diseases increase the risk of developing acute leukemia.
- Myelodysplastic syndrome (MDS) and certain other blood disorders: People with certain blood disorders are at increased risk of acute myeloid leukemia.
- Human T-cell leukemia virus type I (HTLV-I): People with HTLV-I infection are at increased risk of a rare type of leukemia known as adult T-cell leukemia. Although the HTLV-I virus may cause this rare disease, adult T-cell leukemia and other types of leukemia are not contagious.
- Family history of leukemia: It's rare for more than one person in a family to have leukemia. When it does happen, it's most likely to involve chronic lymphocytic leukemia. However, only a few people with chronic lymphocytic leukemia have a father, mother, brother, sister, or child who also has the disease.
Having one or more risk factors does not mean that a person will get leukemia. Most people who have risk factors never develop the disease.