Lymphoma is a type of blood cancer that starts in white blood cells called lymphocytes, which are part of the body’s immune system. When lymphocytes develop genetic mutations (DNA changes), they can start to grow too quickly and live longer than healthy cells. This abnormal growth can lead to cancer. Different factors might increase the risk of lymphoma, including infections, lifestyle choices, genetic disorders, and immune system problems.
The two main types of lymphoma are Hodgkin lymphoma and non-Hodgkin lymphoma (NHL). NHL includes many subtypes, each with specific characteristics and treatments.
Like other cancers, lymphoma develops because of genetic mutations (also called pathogenic variants, or changes), which cause cells to divide and grow in an uncontrolled way. There are two main types of genetic variants — inherited and acquired.
Acquired variants:
Inherited variants:
Both acquired and inherited variants are thought to raise the risk of developing Hodgkin and non-Hodgkin lymphoma. However, doctors still don’t fully understand why some people get lymphoma and others don’t.
Normal cells divide in an organized way to replace old or damaged cells. Certain genes in each cell control when cells should start and stop dividing. Some genes also check for mistakes in the cell’s DNA and either fix them or tell the cell to self-destruct if the DNA is too damaged.
If a genetic mutation causes one or more of these genes to stop working correctly, the cells can divide faster and more chaotically, causing further abnormalities. Mutations can build up, making the cells grow even faster and become more disordered. If these cells spread into nearby tissue or break off and move to other parts of the body, they have become cancerous.
It’s important to know that although science is good at finding correlations (connections) between factors and disease, these links don’t mean that one causes the other. Many risk factors for lymphoma have been identified and are being studied to better understand how they might contribute to the disease.
Since genetic variants cause lymphoma, risk factors include anything that can encourage those changes to happen. Risk factors vary by the type of lymphoma. Hodgkin lymphoma and NHL share some risk factors, and others are more strongly linked — or only linked — to Hodgkin lymphoma, NHL, or specific subtypes of NHL.
Genes passed down from parents may raise the risk of Hodgkin lymphoma. Having a first-degree relative (parent or sibling) with lymphoma may also make you more likely to develop either Hodgkin or non-Hodgkin lymphoma.
Some rare inherited conditions that weaken the immune system may increase lymphoma risk. These include:
Overall, men have a higher risk of developing lymphoma than women, according to a study in the American Journal of Hematology. Follicular lymphoma occurs more commonly in women. Certain rare types of lymphoma are specific to one sex, such as primary testicular lymphoma in men and primary breast lymphoma in women, according to the American Cancer Society.
In the United States, white people are more likely to have NHL than African Americans or Asian Americans, per the American Cancer Society.
Mutations in DNA are inevitable, building up with age. Researchers believe that tens of thousands of mutations may accumulate by the time a person turns 60. However, only a small percentage of people will develop cancer.
Both Hodgkin and non-Hodgkin lymphoma can develop at any age, from childhood through older adulthood. However, NHL becomes more common with age, with most diagnoses made in people in their 60s and older.
Hodgkin lymphoma is most common in two age groups — young adults in their 20s and adults 55 or older. Most Hodgkin lymphoma cases are diagnosed between ages 15 and 34.
Anything that raises the risk of acquired genetic mutations also raises the risk of lymphoma and other types of cancer. Many risk factors for lymphoma involve problems with the immune system.
Non-Hodgkin lymphoma occurs more commonly in developed countries, including the United States and nations in Europe. Researchers aren’t sure why this is, but one idea is that certain infections related to lymphoma might be more widespread in these countries.
Certain infections from viruses and bacteria have been shown to raise the risk of lymphoma.
Bacterial infections often cause chronic inflammation, which can trigger cell mutations leading to lymphoma.
Certain autoimmune health conditions are associated with an increased risk of developing NHL. Researchers haven’t yet established whether this increased risk is due to inflammation caused by the condition itself or to side effects of treatment. Medications for autoimmune conditions generally work by suppressing aspects of the immune system.
Autoimmune conditions associated with a higher risk for NHL include:
Read more about conditions related to lymphoma.
Recipients of organ transplants have a higher risk of non-Hodgkin lymphoma, possibly due to the medications they must take to prevent rejection. People who’ve been treated for Hodgkin lymphoma have a higher risk of developing NHL later on, either due to their treatments or to Hodgkin lymphoma itself.
Some chemotherapy drugs used to treat cancer may increase the risk of developing NHL. Certain medications used to treat autoimmune conditions, including methotrexate (sold as brands such as Otrexup, Rasuvo, Rheumatrex, Trexall, and Xatmep) and tumor necrosis factor inhibitors such as infliximab (Remicade), adalimumab (Humira), golimumab (Simponi), and certolizumab (Cimzia), may be associated with an increased risk of NHL. More studies are needed to better understand these links.
Some studies suggest that Janus kinase (JAK) inhibitors, like tofacitinib (Xeljanz), may increase lymphoma risk in certain high-risk groups, such as people with cardiovascular disease (heart and blood vessel conditions). However, more research is needed to understand this possible risk. JAK inhibitors are used to treat arthritis and other inflammatory diseases.
People who use oral contraceptives may have a lower risk of NHL than those who do not.
Exposure to high levels of ionizing radiation increases the risk of NHL. Sources of ionizing radiation include:
Some chemicals are linked to a higher risk of lymphoma, especially herbicides and pesticides. These include:
Exposure to benzene, a common chemical used in plastics, rubber, dye, detergents, and gasoline, is known to cause cancer in general and may be linked to NHL. Cigarette smoke, including secondhand smoke, contains this chemical and accounts for about half of benzene exposure for people in the U.S.
Non-Hodgkin lymphoma occurs more commonly in agricultural communities, and farm workers tend to develop certain subtypes at a higher rate than people in other occupations. People who work as hairdressers or in the textile industry may also have a higher risk of developing NHL. These jobs and some related hobbies may increase exposure to cancer-causing chemicals, like those listed above.
Obesity is defined as having a body mass index of 30 or higher. Obesity increases the risk of DLBCL and is linked with a 17 percent increased risk of developing chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), another subtype of NHL.
Scientists have identified many acquired genetic mutations in lymphocytes that can lead to lymphoma. Genetic testing of lymphoma cells is often part of the diagnostic process because it helps doctors tell the different types of lymphoma apart. Understanding which mutations are in the cancer cells also helps doctors recommend effective treatment options.
Read more about specific genetic mutations commonly associated with different types of lymphoma.
There’s no certain way to prevent lymphoma. Many people who develop lymphoma have no known risk factors. Most risk factors, including age, genetics, and ethnicity, can’t be controlled. If you’re concerned about your risk, you can take steps like the following to address environmental factors:
If your doctor has told you that you have risk factors for lymphoma, make sure to attend all follow-up appointments for monitoring tests. You may not notice symptoms right away, and early detection may mean additional treatment options and improved outcomes.
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Intersting synopsis. It is sounding like genetic transmission could be more likely. My maternal aunt was diagnosed with stage 4 Non-Hodgkins lymphoma at 79. She lived until 97 with no treatment (… read more
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