Tobacco smoke contains at least 70 chemicals known to cause cancer, such as formaldehyde, nicotine, and lead.

Smoking increases your chances of lung cancer by 15 to 30 times. It’s also been linked to an increased risk of developing many other types of cancer, including lymphoma.

Lymphoma is a cancer that develops in a category of white blood cells called lymphocytes. It’s divided into two primary categories: Hodgkin’s lymphoma (HL) and non-Hodgkin’s lymphoma (NHL).

Researchers have also found some evidence that smoking may be associated with a subcategory of NHL called follicular lymphoma, but studies have found mixed results.

In this article, we review what’s currently known about smoking and the risk of non-Hodgkin’s lymphoma.

About 80,470 people in the United States are predicted to be diagnosed with NHL in 2022. Researchers are continuing to examine a potential link between smoking and NHL. Some studies suggest a possible connection, but current evidence is mixed.

Theoretically, chemicals in tobacco smoke could lead to genetic mutations that cause lymphocytes to replicate uncontrollably. However, the exact mechanism of how smoking could cause lymphoma remains mostly unexplained.

It’s been suggested that cigarette smoking may alter immune response by producing molecules called Th2 cytokines. These molecules may inhibit the destruction of cancerous lymphocytes.

One group of cancer-causing chemicals in tobacco smoke called aromatic hydrocarbons can cause mutations in the TP53 gene.

Mutations in this gene are seen in 5% to 6% of people with follicular lymphoma. These mutations are associated with poorer survival. Follicular lymphoma is the second most common type of NHL.

What are 95% confidence intervals?

Researchers use 95% confidence intervals (CI) to express a range of values they can say with 95% certainty contains the true average.

For example, if they find that people who smoke have a 2.0 times higher chance (95% CI: 1.9 to 2.1) of developing a type of cancer, they can say with 95% certainty that people who smoke have between a 1.9 to 2.1 higher chance of developing that cancer.

Smoking and follicular lymphoma (a subset of non-Hodgkin’s lymphoma)

Some groups of researchers have found a moderate association between smoking and follicular lymphoma, although study results have been conflicting. Follicular lymphoma is a subset of non-Hodgkin’s lymphoma.

In a 2020 review of studies, researchers found that most studies didn’t support an association between smoking and follicular lymphoma.

However, a 2022 review of studies by the same lead author found consistent evidence between smoking and increased follicular lymphoma risk. Researchers also found:

  • evidence of higher risk with an increased amount of smoking
  • an association between smoking and poorer survival after diagnosis
  • that smoking was possibly associated with poorer follicular lymphoma-specific survival
  • increased risk of follicular lymphoma among nonsmokers who were exposed indoors to more than two smokers during childhood

In a 2018 study, researchers examined cancer rates among 211,005 smokers and 211,005 nonsmokers over a 30-year period. They found:

  • Male smokers had a 7% higher (95% CI: 4% to 7%) and female smokers had a 3% (95% CI: 0% to 6%) higher chance of developing any cancer than nonsmokers.
  • Men who smoked had a 24% (95% CI: 13% to 36%) higher chance than nonsmokers of developing lymphoma.
  • Female smokers had a 2% (95% CI: -7% to 11%) increased chance of developing lymphoma. These CIs mean it wasn’t clear whether they were at a higher or lower chance of developing lymphoma.

Smoking and Hodgkin’s lymphoma

Current research suggests that smoking is most associated with the development of HL and a subcategory of NHL called follicular lymphoma.

Studies suggest that smoking cigarettes is associated with a modestly increased risk of HL but a 60% to 80% increased risk of some subtypes.

In a 2005 study, researchers found that smoking may increase the risk of follicular lymphoma but not other subtypes of NHL.

A more recent 2017 study found that people smoking more than 15 cigarettes a day had a 42% (95% CI: 2% to 97%) increased risk of developing NHL and a 147% (95% CI: 25% to 387%) increased risk of HL.

No increased risk was found for people smoking fewer than 15 cigarettes a day or former smokers. Smoking duration was associated with increased HL risk but not NHL risk.

Immune suppression and viral infections are the most important risk factors of NHL. Other risk factors include:

  • older age
  • male sex, except for some cancer subtypes, like follicular lymphoma, that are more common in females
  • being white, compared with African Americans and Asian Americans
  • family history
  • exposure to some drugs, such as benzene, and some herbicides
  • radiation exposure
  • autoimmune disease
  • overweight or obesity, but more research is needed to confirm this

Smoking is considered the strongest negative predictor of survival in people with cancer. Smoking after cancer diagnosis is associated with:

  • increased treatment toxicity
  • higher risk of treatment failure
  • higher risk of a second cancer
  • poorer quality of life

Chemicals in smoke may impair your liver’s ability to metabolize chemicals in chemotherapy drugs and increase your risk of complications.

Early studies suggest that nicotine may impair the effectiveness of chemotherapy by activating pathways that stimulate cell growth and inhibiting programmed cellular death.

Nicotine is also found in e-cigarette products. One 2022 study found that e-cigarette users had 2.2 times the risk of having cancer than nonsmokers.

Some small studies have found that smoked cannabis may help treat nausea and vomiting caused by cancer chemotherapy.

In a 2020 study, researchers found that current smoking was associated with lower quality of life at diagnosis and at a 3-year follow-up in 2,805 lymphoma survivors.

A 2012 study found evidence that cigarette smoking before NHL diagnosis was associated with poorer survival in people with NHL. The association was strongest for people diagnosed under the age of 60 and with follicular lymphoma.

They also found that a longer time following quitting smoking may be associated with improved survival in former smokers.

Continuing to smoke can also increase your risk of developing a secondary cancer.

Here are some frequently asked questions people have about smoking and NHL.

Can secondhand smoke exposure increase your risk of non-Hodgkin’s lymphoma?

In a 2022 review of studies, researchers found that the risk of follicular lymphoma increased with indoor exposure to more than two smokers during childhood but not during adulthood.

These results were consistent with previous studies that found risk tended to increase with total years and intensity of exposure.

Can smoking affect your immune system?

Substantial research suggests that smoking harms your immune system and makes your body less capable of fighting disease. Smoking also increases the risk of some autoimmune diseases, such as rheumatoid arthritis.

If I smoked before being diagnosed with NHL but stopped after diagnosis, will that affect my outlook?

People who quit smoking after a cancer diagnosis tend to live longer and have a better chance of successful treatment. They also have fewer treatment side effects than people who continue to smoke.

Can alcohol consumption increase your risk of non-Hodgkin’s lymphoma?

A 2020 review of studies found consistent evidence that increased alcohol intake is associated with an increased risk of follicular lymphoma.

Smoking increases your risk of developing many types of cancer.

Researchers have found more evidence to support a connection between smoking and HL than NHL. However, some studies suggest a link between smoking and a particular type of NHL called follicular lymphoma. It’s not clear how strong this association is.

Quitting smoking after a cancer diagnosis can help improve the effectiveness of your treatment and improve your outlook.

Quitting smoking can be difficult, but there are many resources available to help make it easier. Learn more about quitting smoking here.