Leukemia is a cancer of the body’s bone marrow, which is where your blood cells are made. It’s a genetic disease, but most cases aren’t thought to be hereditary. Instead, a variety of risk factors can make you more likely to get the disease. Some of these risk factors are in your control, others aren’t.
Scientists think the various types of leukemia are caused by mutations in the DNA of your blood cells. These genetic mutations change the way the blood cells in your bone marrow reproduce. They can also prevent these blood cells from functioning properly. Eventually, the abnormal blood cells crowd out your healthy blood cells. They can block your bone marrow from producing more healthy cells.
The mutations are genetic, but usually not hereditary. This means that while leukemia is caused by mutations in your genes, these genetic abnormalities aren’t often inherited from your family. This is called an acquired gene mutation.
It’s not always known what causes these mutations. You may be genetically predisposed to developing leukemia, but lifestyle risk factors, such as cigarette smoking, can also make you more likely to develop leukemia. Other environmental factors, such as exposure to certain chemicals and radiation, could also be behind the DNA abnormalities that can cause leukemia.
These two terms aren’t interchangeable, although they both refer to diseases that are caused by mutations in your genes. Let's take a closer look.
A genetic disease isn’t always one that is passed down through your family. A genetic disease is any medical condition caused by a DNA abnormality, whether it’s inherited or acquired. This DNA abnormality is caused by a mutation in one gene or multiple genes.
The mutations can take place during your lifetime as errors occur in cell production. They can also be caused by environmental factors. These environmental factors include exposure to radiation or certain chemicals.
A hereditary disease is a type of genetic disease in which the gene mutations are inherited from your family. The gene mutations are present in the egg or sperm and cause the disease to be passed from parents to their children. Some examples of hereditary diseases include hemophilia, sickle cell anemia, and muscular dystrophies. It’s rare for these types of hereditary diseases to suddenly appear in someone with no family history of them.
There are some types of hereditary cancers, as well. For example, breast, ovarian, colorectal, and prostate cancers have hereditary elements that may put families at risk.
A risk factor is some element about you, your genetics, or your environment that can make you more likely to develop a disease. Disease risk factors aren’t the same thing as disease causes. Having a risk factor means that you have an increased chance of developing the disease, but you may not get the disease even if you meet the risk factors.
For example, age is often listed as a risk factor for various diseases. Aging itself isn’t the cause of the disease. What makes it a risk factor is that the disease is seen more often in older adults.
Leukemia has slightly different risk factors depending on the type. The four types of leukemia are:
- acute myeloid leukemia (AML)
- acute lymphocytic leukemia (ALL)
- chronic myelogenous leukemia (CML)
- chronic lymphocytic leukemia (CLL)
Risk factors that make you more likely to develop one of these four types of leukemia are listed below.
Having certain genetic disorders can increase your risk of also developing AML and ALL. These conditions include:
- Klinefelter syndrome
- Fanconi anemia
- Down syndrome
- Li-Fraumeni syndrome
- Bloom syndrome
This lifestyle-related factor can increase your risk of AML. This is one of the few things that you can change to help reduce your risk of leukemia.
Certain blood disorders can also put you at risk of developing AML. These include:
Exposure to certain chemicals
Frequent exposure to some chemicals increases the risk of AML, ALL, and CLL. One of the main chemicals that has been linked to leukemia is benzene. Benzene is found in:
- oil refineries
- shoe manufacturing plants
- the rubber industry
- chemical plants
People who have been exposed to Agent Orange, a chemical used during the Vietnam War, have an increased risk of developing CLL.
Previous cancer treatments
Radiation is a risk factor for AML, ALL, and CML. This means that people who have gone through cancer radiation treatments have an increased risk of leukemia.
Previous cancer treatment with certain chemotherapy drugs is also a risk factor for leukemia. These drugs include:
- alkylating agents
- platinum agents
- topoisomerase II inhibitors
You have increased risk of developing leukemia if you’ve had both chemotherapy and radiation treatment. A review article from 2012 explains that many scientists agree that the dose of radiation used in diagnostic testing is enough to induce cancer. However, the review also explains that potential benefits of testing may outweigh the risk of radiation exposure.
The risk of developing AML and CLL increases with age.
Men are slightly more likely than women to develop all four types of leukemia.
Researchers have found that certain groups of people are more likely to develop some types of leukemia. For example, people of European descent have an increased risk of CLL. Researchers also found that leukemia is rare in people of Asian descent. These different risks are likely due to different genetic predispositions.
Leukemia is generally not considered a hereditary disease. However, having a close family member with leukemia increases your risk of chronic lymphocytic leukemia. According to a 2013 paper published in Seminars in Hematology, research points to an inherited factor for CLL. This leukemia does occur more often in people who have a close family member who also had leukemia. Close family members are medically defined as your first-degree family, meaning your father, mother, and siblings.
People with identical twins who developed acute lymphocytic leukemia before the age of 12 months also have an increased risk of that type of leukemia.
Infection with the human T-cell lymphoma/leukemia virus-1 has been found to be a risk factor for ALL. This is more commonly found in Japan and the Caribbean, according to the American Cancer Society.
It’s important to note that even for people who have some of these risk factors, most won’t get leukemia. The opposite is also true: People who have no risk factors can still be diagnosed with leukemia.
Some risk factors aren’t preventable. Even people who have no risk factors can still be diagnosed with leukemia, so there is no way to absolutely prevent leukemia. However, there are a few things you can do to lower your risk.
- Stop smoking, or don’t start in the first place.
- Avoid close contact with high-risk chemicals, such as benzene.
- Avoid exposure to radiation.
- Exercise and eat a healthy diet to support a strong immune system.
A 2004 study has found a link between breastfeeding and lower risk of leukemia in children.
If you work in an industry that brings you in close contact with benzene, it’s important to let your doctor know. You should also let your doctor know if you’ve been exposed to radiation and chemotherapy drugs during previous cancer treatment. Your doctor can do blood tests to check you for leukemia. Testing won’t prevent the leukemia from developing, but an early diagnosis gives the best chance for an early recovery.
If you have any of the following symptoms, you should make an appointment with your doctor for blood tests to confirm or rule out leukemia:
- extreme pain in your joints
- nighttime sweating
- frequent infections
- loss of appetite
- weight loss
- bruising easily
- unexplained bleeding
Leukemia symptoms often resemble much more common health issues, like the flu. However, the symptoms may be more severe. Because leukemia affects your white blood cells, frequent infections may indicate something more serious than the flu. If you have flu-like symptoms or other infections that are more frequent than usual, call your doctor and ask for a blood test.