A study assessing whether there is an association between cannabis use disorder and head and neck cancer (HNC) has revealed some unsettling results.
Cannabis is being increasingly used to manage some symptoms associated with cancer. But can it also trigger it?
A cohort study of 116,076 US adults found those with cannabis use disorder (CUD) had an increased risk of any HNC compared with a group of matched individuals. CUD is the continued use of cannabis despite significant negative impacts on a person’s life or health. Furthermore, there was an elevated risk of oral, oropharyngeal, nasopharyngeal, salivary gland, and laryngeal cancer,
The study included clinical records from a database covering 20 years of data through to April this year from dozens of healthcare providers.
Commenting on the results from the study, co-author Joseph Califano, MD said he was concerned the same mistakes of the past made with smoking tobacco are being repeated.
“Are we watching cannabis use rapidly expand with the support of a powerful industry, the public, and our legislators, only to discover years later, after the genie has escaped the bottle, that cannabis is carcinogenic?” he said.
What isn’t clear from the study and additional commentary abstracts are methods of consumption. This is important as combusting (burning) any plant material may result in the production of carcinogens. Marijuana smoke has been found to have some of the same harmful chemicals and compounds found in tobacco smoke, but the jury is still out on whether it can cause cancer.
But cannabis or its extracts can be administered in a variety of other forms, including oils, edibles, patches and capsules – but again, there’s no reliable evidence indicating whether these options elevate cancer risk.
Given the limitations of the database used, the study authors state future research should delve into the mechanism of the association and dose response with strong controls.
The study has been published in JAMA Otolaryngology–Head & Neck Surgery.
In Australia during 2020, there were 1,177 deaths from head and neck cancer (including lip) – 873 males and 304 females. However, information on the proportion of these deaths in terms of persons also having CUD isn’t available.
