Risk factors for non-Hodgkin's lymphoma (2023)

A risk factor is anything that increases your chances of developing a disease such as cancer. Different types of cancer have different risk factors. Some risk factors, such as smoking, can be modified. Others, such as a person's age or family history, may not.

But having one risk factor, or even several risk factors, does not mean you will get the disease. Many people with this condition may have few or no known risk factors.

Researchers have identified several factors that may affect a person's chance of developing non-Hodgkin's lymphoma (NHL). There are many types of lymphomas, and some of these factors are only associated with certain types.

age

Overall, aging is a major risk factor for lymphoma, with most cases occurring in people age 60 and older. But certain types of lymphoma are more common in younger people.

sex

In general, men are at greater risk of developing NHL than women, but some types of NHL are more common in women. The reason for this is not clear.

Race, ethnicity and geography

In the United States, whites are more likely to develop NHL than African Americans and Asian Americans.

Globally, NHL is most common in developed countries, with the highest rates in the United States and Europe. Certain types of lymphoma are associated with certain infections (described later) that are more common in certain parts of the world.

family history

Having a first-degree relative (parent, child, sibling) with NHL increases your risk of developing NHL.

exposure to certain chemicals and drugs

Some research suggests that chemicals such as benzene and certain herbicides and insecticides (substances that kill weeds and insects) may be associated with an increased risk of NHL. Research to clarify these possible links is still ongoing.

Some chemotherapy drugs used to treat other types of cancer can increase your risk of NHL years later. For example, patients treated for Hodgkin lymphoma have an increased risk of developing NHL later in life. But it is not entirely clear whether this has something to do with the disease itself or whether it is an effect of the treatment.

Some research suggests that certain medications used to treat rheumatoid arthritis (RA), such as methotrexate and tumor necrosis factor (TNF) inhibitors, may increase the risk of NHL. But other studies have found no increased risk. Determining whether these drugs increase risk is complicated because people with RA, an autoimmune disease, are already at increased risk of developing NHL (see below).

exposure to radiation

Studies of survivors of nuclear bomb and nuclear reactor accidents have shown an increased risk of several cancers, including NHL,leukemia, ethyroid cancer。

People receiving radiation therapy for other types of cancer, such asHodgkin lymphoma, with a slightly increased risk of developing NHL later in life. This risk is greater in patients receiving radiotherapy and chemotherapy.

weak immune system

People with weakened immune systems are at greater risk for NHL. For example:

• People undergoing organ transplants are treated with drugs that suppress the immune system to prevent it from attacking the new organ. These people are at greater risk for NHL.
• areHuman Immunodeficiency Virus (HIV)It can weaken the immune system and increase the risk of NHL in HIV-infected people.
• In some hereditary (genetic) syndromes, such as ataxia-telangiectasia (AT) and Wiskott-Aldrich syndrome, children are born with a faulty immune system. In addition to an increased risk of serious infections, these children are also at increased risk of developing NHL.

autoimmune disease

Some autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus (SLE or lupus), xerosis (Sjogren's disease), celiac disease (gluten sensitive enteropathy), and others are associated with an increased risk of NHL.

In autoimmune diseases, the immune system mistakenly perceives the body's own tissues as foreign and attacks them, just as it would attack bacteria. Lymphocytes (the cells that initiate lymphomas) are part of the body's immune system. An overactive immune system in autoimmune diseases can cause lymphocytes to grow and divide more often than normal. This can increase your risk of developing lymphoma cells.

certain infections

Certain types of infections can increase the risk of NHL in different ways.

Infection of directly transformed lymphocytes

Some viruses can directly affect the DNA of lymphocytes, which can turn them into cancer cells:

• Infection with human T-cell lymphotropic virus (HTLV-1) increases the risk of certain types of T-cell lymphoma. The virus is most common in parts of Japan and the Caribbean, but has been found worldwide. It causes less than 1% of lymphomas in the United States. HTLV-1 is transmitted sexually and through infected blood and can be passed from infected mothers to children through breast milk.
• In some parts of Africa, infection with the Epstein-Barr virus (EBV) is a major risk factor for Burkitt lymphoma. In developed countries such as the United States, EBV is often associated with lymphoma in people co-infected with HIV, the virus that causes AIDS. The Epstein-Barr virus has also been linked to some less common forms of lymphoma.
• Human herpesvirus 8 (HHV-8) can also infect lymphocytes, causing a rare type of lymphoma called primary effusion lymphoma. This lymphoma is most common in patients with HIV infection. HHV-8 infection has also been linked to another type of cancer,Kaposi's sarcoma. So another name for this virus isHerpes virus associated with Kaposi's sarcoma(KSHV)。

Infections that weaken the immune system

Infection with the human immunodeficiency virus (HIV), also known as AIDS, weakens the immune system. HIV infection is a risk factor for certain types of NHL, such as primary central nervous system lymphoma, Burkitt's lymphoma, and diffuse large B-cell lymphoma.

Infections that cause chronic immune stimulation

Some long-term infections can force the immune system to stay active, increasing the risk of lymphoma. As more lymphocytes are produced to fight infection, important genes are more likely to mutate, which can eventually lead to lymphoma. Some lymphomas related to these infections improve after the infection is treated.

• Helicobacter pyloriA bacteria known to cause stomach ulcers has also been linked to gastric mucosa-associated lymphoid tissue (MALT) lymphoma.
• Chlamydia psittaci(formerly known asChlamydia psittaci) is a bacteria that can cause lung infectionspsittacose. It is associated with MALT lymphoma in the tissues around the eyes (so-calledOcular adnexal marginal zone lymphoma）。
• bacterial infectionsCampylobacter jejuniAssociated with a type called MALT lymphomaimmunoproliferative disease of the small intestine. This type of lymphoma is sometimes calledMediterranean abdominal lymphomausually occurs in young people in the Eastern Mediterranean countries.
• Long-term infection with the hepatitis C virus (HCV) appears to be a risk factor for certain types of lymphomas, such as splenic marginal zone lymphoma.

body weight

some studies showoverweight or obeseIt may increase the risk of NHL. More research is needed to confirm these findings. in each case,maintain a healthy weight,stay physically active, and followhealthy eating patternsEating plenty of fruits, vegetables, and whole grains and limiting or avoiding red and processed meats, sugary drinks, and highly processed foods has many well-known health benefits, in addition to potentially reducing the risk of lymphoma.

breast implants

Although rare, some women with breast implants may develop lymphomas in the scar tissue (capsule) that forms around the implant. Most of them involve a rare form of T-cell lymphomarelated breast implantAnaplastic Large Cell Lymphoma (BIA-ALCL), but other types of NHL have also been reported.