In a study reported in JAMA Otolaryngology–Head & Neck Surgery, Gallagher et al found that individuals with cannabis-related disorder were at an increased risk of head and neck cancer vs those without cannabis-related disorder. Cannabis-related disorders are defined by the excessive use of cannabis with associated psychosocial symptoms.
Study Details
The study focused on clinical records from a database that included 20 years of data (through April 2024) from 64 U.S. health-care organizations accounting for more than 90 million individuals. The database was searched for records of adults with and without cannabis-related disorder who had recorded outpatient hospital clinic visits and no history of head and neck cancer. Propensity score–matching was performed using demographic characteristics, alcohol-related disorders, and tobacco use.
Key Findings
The cannabis-related disorder cohort included 116,076 individuals (44.5% women, mean age = 46.4 ± 16.8) years); the non–cannabis-related disorder cohort included 3,985,286 individuals (54.5% women, mean age = 60.8 ± 20.6 years). The rate of new head and neck cancer diagnosis was higher in the cannabis-related disorder cohort at all head and neck cancer sites, including any head and neck cancer (0.285% vs 0.091%), hypopharyngeal cancer (0.016% vs 0.003%), laryngeal cancer (0.093% vs 0.015%), and nasopharyngeal cancer (0.022% vs 0.007%).
In a propensity score–matching analysis, including 115,865 individuals in each cohort, individuals with cannabis-related disorder had a significantly greater risk of any new head and neck cancer diagnosis (risk ratio [RR] = 3.49, 95% confidence interval [CI] = 2.78–4.39), as well as significantly greater risks of oral (RR = 2.51, 95% CI = 1.81–3.47), oropharyngeal (RR = 4.90, 95% CI = 2.99–8.02), laryngeal (RR = 8.39, 95% CI = 4.72–14.90), nasopharyngeal (RR = 2.60, 95% CI = 1.25–5.39), and salivary gland cancers (RR = 2.70, 95% CI = 1.31-5.58) but not hypopharyngeal cancer (RR = 1.70, 95% CI = 0.78–3.71). Similar results were observed in analysis by younger and older age groups.
The investigators concluded: “This cohort study highlights an association between cannabis-related disorder and the development of head and neck cancer in adult patients. Given the limitations of the database, future research should examine the mechanism of this association and analyze dose response with strong controls to further support evidence of cannabis use as a risk factor for head and neck cancers.”
Niels C. Kokot, MD, of the Caruso Department of Otolaryngology–Head and Neck Surgery, Keck School of Medicine, University of Southern California, is the corresponding author of the JAMA Otolaryngology–Head & Neck Surgery article.
Disclosure: For full disclosures of the study authors, visit jamanetwork.com.
