John Brooks, DDS, a dentist and clinical professor at the University of Maryland School of Dentistry in Baltimore, recently cowrote an article in a major dentistry journal laying out the research for his colleagues — most recently a study published in 2024 of adults diagnosed with cannabis use disorder.
“The study established a strong link between smoking cannabis and the development of cancer of the head and neck, and corroborated the findings of smaller-sized studies,” says Dr. Brooks.
Marijuana Use Could Raise the Risk of Head and Neck Cancer Up to Eightfold
Researchers who conducted that study found that the risk of head and neck cancer — particularly laryngeal, oropharyngeal, oral, and salivary cancers — was 2 to 8 times higher for people with cannabis use disorder compared with people without.
Smoking May Pose Greater Risks Than Edibles, but More Research Is Needed
The study didn’t delve into how participants consumed cannabis, such as smoking, ingesting edibles, or vaping. But Brooks notes that smoking is the most common method.
“There is a large volume of literature that has demonstrated various carcinogens in cannabis smoke and tobacco smoke,” Brooks says. “Thus, these carcinogens play a [likely] role in the development of head and neck cancer.”
In their journal article, Brooks and his coauthors point out that cannabis smoke — which users often inhale more deeply than tobacco smoke, without filtration — contains compounds known to damage DNA and promote inflammation and tumor growth.
“We know that smoking in general is associated with an increased risk of head and neck cancers,” says Richard Lee, MD, a medical oncologist and medical director of supportive and integrative medicine at City of Hope in Duarte, California. Dr. Lee was not involved with the new article.
“Anytime you’re exposed to the byproducts of burning materials — whether it’s smoking cannabis or cigarettes — you’re exposing those bodily tissues to smoke, and we know there are carcinogens in smoke itself,” he explains.
Whether there’s also a cancer risk associated with marijuana edibles is an area for future study, Lee says.
Additional research should also address the dose of cannabis related to the risk for head and neck cancer, Brooks says, as well as the potential risks of medical marijuana.
What Is Head and Neck Cancer?
Symptoms of head and neck cancer can include:
- Red or white patches on the gums, tongue, or lining of the mouth
- Growths or swelling of the jaw
- Bleeding or pain in the mouth
- Pain when swallowing
- Pain in the neck, throat, or ears
- Problems with hearing
- Problems breathing or speaking
- Chronic sinus infections that don’t respond to treatment
- Swelling under the chin or around the jaw
- Numbness in facial muscles
“This manuscript provides a nice summary of the clinical and molecular data, potentially drawing links between cannabis use and head and neck cancer risk,” says Alan Ho, MD, chief of head and neck oncology service at Memorial Sloan Kettering Cancer Center in New York City, who was not involved with the new article.
“But more research is needed to definitely establish these links and clarify what components of cannabis and routes of ingestion are the most relevant for cancer risk,” Dr. Ho says.
How Many Americans Use Marijuana?
Ho says more research is needed on the use of cannabis in different clinical settings “to provide the evidence practitioners require to provide clear and informed advice to patients.”
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