In a study conducted in JAMA Otorhinolaryngology – Head and Neck SurgeryGallagher et al. found that individuals with cannabis-related disorder were at higher risk for head and neck cancer than individuals without cannabis-related disorder.

Study details

The study focused on medical records from a database that included 20 years of data (through April 2024) from 64 U.S. healthcare organizations covering more than 90 million individuals. The database was searched for records of adults with and without cannabis-related disorder who had recorded outpatient hospital visits and had 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 disease cohort included 116,076 individuals (44.5% female, mean age = 46.4 ± 16.8 years); the non-cannabis-related disease cohort included 3,985,286 individuals (54.5% female, mean age = 60.8 ± 20.6 years). The rate of new head and neck cancer diagnoses was higher in the cannabis-related disease cohort across all head and neck cancer sites, including 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-matched analysis with 115,865 individuals in each cohort, individuals with a cannabis-related disorder had a significantly higher risk of a new head and neck cancer diagnosis (risk ratio (RR) = 3.49, 95% confidence interval (CI) = 2.78–4.39), as well as a significantly higher risk of oral cancer (RR = 2.51, 95% CI = 1.81–3.47), oropharyngeal cancer (RR = 4.90, 95% CI = 2.99–8.02), laryngeal cancer (RR = 8.39, 95% CI = 4.72–14.90), nasopharyngeal cancer (RR = 2.60, 95% CI = 1.25–5.39), and salivary gland cancer (RR = 2.70, 95% CI = 1.31–5.58), but not hypopharyngeal carcinoma (RR = 1.70, 95% CI = 0.78–3.71). Similar results were observed when analyzing younger and older age groups.

The researchers concluded: “This cohort study demonstrates an association between cannabis-related diseases and the development of head and neck cancer in adult patients. Given the limited database, future research should investigate the mechanism of this association and analyze the dose-response relationship with rigorous controls to provide evidence that cannabis use is a risk factor for head and neck cancer.”

Niels C. Kokot, MDfrom the Caruso Department of Otolaryngology, Head and Neck Surgery, Keck School of Medicine, University of Southern California, is the corresponding author of the JAMA-OLaryngology – Head and Neck Surgery Article.

Announcement: Full details of the study authors can be found at jamanetwork.com.