Leukemia comes in a variety of types, some of which you may be more likely to develop than others, according to Sean Fischer, M.D., medical oncologist and hematologist at Providence Saint John’s Health Center in Santa Monica, California. Here are some of the most common risk factors.
Although leukemia is often thought of as a childhood disease—which makes sense, since it accounts for 1 out of 3 childhood cancers—the risk for most leukemias typically increases with age. The exception is a type called acute lymphocytic leukemia (ALL), which is the type most commonly seen in children. By contrast, another type called acute myeloid leukemia (AML) mainly occurs in adults over age 60.
Leukemia is more common in men than women. The cancer is the fifth leading cause of cancer-related mortality among men, and the seventh leading cause among women, highlighting the gender difference.
Just like chemo, radiation done to eradicate other cancers can create a risk for leukemia development. Dr. Fischer notes that the risk is highest in the period from five to nine years after radiation treatment has concluded.
There are few lifestyle-related risk factors for leukemia, but smoking is one of them, particularly for AML. That’s likely because cigarette smoke contains benzene, a chemical that’s been linked to leukemia development.
Another risk factor for AML specifically is the existence of certain bone marrow disorders called myelodysplastic syndromes, some of which can be caused by radiation or chemotherapy treatment for a previous cancer.
Certain genetic abnormalities may play a role in leukemia development. The most common is Down syndrome—children with this condition are many times more likely to develop leukemia than other children.
Unlike some cancers, leukemia usually doesn’t have a direct link to family history. However, there are some exceptions. Siblings of children with leukemia have two to four times more chance of developing leukemia themselves; identical twins even more so. If you have a parent, sibling, or child with chronic lymphocytic leukemia (CLL), you will have two to four times more risk of developing CLL as well.
Although it’s not yet known why, ethnicity can be a factor for developing leukemia. For example, Hispanic children are at higher risk than other ethnicities for ALL, while African-American children are at the lowest risk for that leukemia type.
In addition to radiation and chemotherapy, other chemical exposure could cause a higher leukemia risk. These can include herbicides used in farming, for example, or persistent exposure to benzene or gasoline.
Having prolonged exposure to electromagnetic fields, such as living for an extended time near power lines, may increase risk for developing ALL. This is considered very uncommon, but still may be a factor for a small number of patients.
Keep in mind that you might have none of these risk factors and still develop leukemia. Similarly, people with multiple risk factors don’t necessarily get leukemia, so simply having increased risk doesn’t mean cancer is inevitable.