Causes and Risk Factors of Leukemia

Leukemia is a cancer that affects the blood cells and develops in blood-forming tissues like the bone marrow. Leukemia occurs when the bone marrow produces abnormal cells that grow and spread uncontrollably, crowding out the healthy cells and keeping them from functioning correctly.

Anyone can develop leukemia, but certain factors can raise your risk, such as smoking, chemical exposure, and a history of cancer treatments. Many people who receive a leukemia diagnosis do not have any of the known risk factors. 

Leukemia occurs when the bone marrow begins to produce abnormal cells. This happens when the bone marrow cells’ genetic material (aka DNA) mutates or changes. Your DNA makes up your chromosomes, which carry genetic information and control how your cells will function. 

Genetic mutations can be harmful because your genes control how the cells grow, divide, and make new cells. When a genetic mutation occurs, the cell does not function properly. Leukemia usually occurs due to a mutation in your oncogenes or tumor suppressor genes. Oncogenes control how cells grow and stay alive, while tumor suppressor cells control cell growth and division. 

Each time a cell divides, it makes a new copy of its DNA. Every time this happens, there is a chance of another mutation. The most common mutations that lead to leukemia cell growth include:

• Translocation: Occurs when part of one chromosome breaks off and attaches to a different chromosome
• Deletion: Occurs when part of the chromosome is missing
• Inversion: Occurs when part of the chromosome is in reverse order
• Duplication (addition): Occurs when a chromosome has an extra part or chromosome

Researchers do not know why these genetic changes occur in the cells. However, there are known risk factors that may contribute to a person’s risk of developing leukemia. 

Leukemia occurs when there is a genetic mutation in certain blood cells. In most cases, these mutations are acquired, meaning you gain the mutation over time rather than being born with it. Leukemia is not considered hereditary, but if you have a close relative, like a parent or sibling, with leukemia, you have a higher risk of developing the condition yourself. 

Certain genetic disorders can raise the risk of leukemia. People with Down syndrome, trisomy 8, and neurofibromatosis type 1 have a higher chance of developing some types of leukemia. 

Some people are more likely to develop leukemia than others. Several factors affect your risk of leukemia, including:

• Age: Older individuals over 50 are at a higher risk of most leukemias. Acute lymphocytic leukemia (ALL) can also occur in children.
• Sex: Many types of leukemia are more common in people assigned male at birth than those assigned female at birth.  
• Race: Certain types of leukemia, such as ALL, are more common in white people.

Some risk factors can increase your chances of developing leukemia. It is important to remember that having a risk factor for a disease does not mean that you will automatically develop it. Similarly, many people with leukemia don’t have any known risk factors when they receive their diagnosis.

Smoking

Smoking is the only proven lifestyle-related risk factor for leukemia. Smoking is linked with several types of cancers because the chemicals in cigarette smoke are known to cause mutations in the DNA. 

When you smoke tobacco, you inhale the smoke into your lungs. Your body tissues then absorb these chemicals and spread them through the bloodstream, which can affect the function of your blood cells. 

Chemical Exposure

Exposure to certain chemicals increases the risk of leukemia. Benzene is a known carcinogen; this means that research has found that the chemical causes cancer. You can find benzene in:

• Cigarette smoke 
• Gasoline
• Motor vehicle exhaust 
• Some cleaning products
• Certain types of paint 
• Many types of hand sanitizers

People who work in the following environments may also be at a higher risk of benzene exposure: 

• Chemical plants 
• Oil refineries 
• Shoe manufacturing 
• Rubber industries 
• Gasoline-related industries

More research is needed to determine if there are additional leukemia risk factors. Some early studies believe that exposure to these substances may also boost your risk of leukemia and other cancers: 

• Electromagnetic fields
• Diesel gasoline
• Herbicides or pesticides 

Cancer Treatments 

Some cancer treatments raise the risk of developing a different type of cancer in the future. Chemotherapy drugs called alkylating agents increase the risk of leukemia. A different kind of chemotherapy known as topoisomerase II inhibitors is also linked to an increased risk of acute myeloid leukemia (AML).

If you have a history of cancer and used radiation during your treatment, you may have a higher risk of developing leukemia. High doses of radiation from an atomic bomb or nuclear reactor accident are known to cause leukemia. 

Blood Disorders

People with certain blood disorders may have a higher chance of developing leukemia. Talk with your healthcare provider about your leukemia risk if you have a history of polycythemia vera, essential thrombocythemia, or idiopathic myelofibrosis.

Certain Infections

Some viral infections have been linked with an increased risk of ALL, which is a specific type of leukemia. Epstein-Barr virus (EBV) and human T-cell lymphoma/leukemia virus-1 (HTLF-1) can raise the risk of cancer. 

Leukemia is a cancer that forms in the bone marrow and develops in the red blood cells, white blood cells, or platelets. Genetic mutations in these cells can cause your bone marrow to produce abnormal or cancerous cells that grow and multiply, leading to leukemia.

Certain factors can also raise your risk of leukemia, such as smoking, exposure to certain chemicals, and a prior history of cancer treatments like chemotherapy and radiation.