Cannabis-Use Disorder Demonstrates a Link With Developing Head and Neck Cancer

Cannabis-related disorder was associated with the development of head and neck cancer in adult individuals, according to data from a multicenter cohort study published in JAMA Otolaryngology–Head & Neck Surgery.

Individuals with cannabis-related disorder (n = 116,076) had a higher rate of new head and neck cancer diagnoses vs those without cannabis-related disorder (n = 3,985,286), which was also true following a propensity score matching of 115,865 individuals per group (relative risk [RR], 3.49; 95% CI, 2.78-4.39). A site-specific analysis also revealed that those who had cannabis-related disorder had a higher risk of developing oral (RR, 2.51; 95% CI, 1.81-3.47), oropharyngeal (RR, 4.90; 95% CI, 2.99-8.02), and laryngeal (RR, 8.39; 95% CI, 4.72-14.90) cancers.

“Tobacco consumption remains a primary risk factor for the development of HPV-negative head and neck cancers,” Tyler J. Gallagher, BS, an MD candidate at Keck School of Medicine of the University of Southern California in Los Angeles, and coauthors wrote. “The smoke content of cannabis contains carcinogens similar to those found in tobacco. Furthermore, tetrahydrocannabinol, the major compound in cannabis, can activate the transcription of specific enzymes that convert polycyclic aromatic hydrocarbons into carcinogens.”

The multicenter retrospective cohort study used clinical records from a globally federated database of deidentified electronic medical records, TriNetX, encompassing 20 years of data from 64 health care organizations. The data accounted for more than 90 million individuals and the cohorts were defined by either a diagnosis or hospital visit occurring from April 19, 2004, to April 19, 2024.

Both cohorts included individuals with a recorded outpatient hospital clinic visit who did not have a history of head and neck cancer, and the individuals in the cannabis-related disorder cohort received a diagnosis of cannabis-related disorder whereas those in the no cannabis-related cohort never received a diagnosis. Groups were also created stratifying individuals by age (< 60 years vs ≥ 60 years).

Gallagher and coauthors noted that cannabis-related disorder is “defined by the excessive use of cannabis with associated psychosocial symptoms, such as impaired social and/or occupational functioning.”

After propensity matching individuals had a mean age at index of 42.2 years in the cannabis-related disorder cohort vs 42.5 years in the no cannabis-related disorder cohort. Most individuals were male (52.9% vs 53.0%) and White (60.0% vs 60.5%). Per International Statistical Classification of Diseases, prior alcohol use (22.5% vs 22.6%) and tobacco use (18.4% vs 18.5%) were reported.

Additional findings showed that the incidence of any head and neck cancer was greater in the cannabis-disorder group (0.285%) vs the no cannabis-disorder group (0.091%), as well as at every location any time after the index event. The highest rates of head and neck cancer occurring by type of cancer in the cannabis-disorder group vs the no cannabis-disorder group, respectively, were oral (0.113% vs 0.049%) and laryngeal (0.093% vs 0.015%).

Following propensity score matching, individuals in the cannabis-disorder cohort had an increased risk of developing any head and neck cancer vs those in the no cannabis-disorder cohort any time after the index event (RR, 3.49; 95% CI, 2.78-4.39). The risk was also elevated for developing laryngeal (RR, 8.39; 95% CI, 4.72-14.90), nasopharyngeal (RR, 2.60; 95% CI, 1.25- 5.39), oral (RR, 2.51; 95% CI, 1.81-3.47), oropharyngeal (RR, 4.90; 95% CI, 2.99-8.02), and salivary gland (RR, 2.70; 95% CI, 1.31-5.58) cancers. However, those with hypopharyngeal cancer did not experience an increased risk in the cannabis-disorder cohort vs the no cannabis-disorder cohort (RR, 1.70; 95% CI, 0.78-3.71). The investigators also noted that findings were consistent when individuals were stratified by age.

Furthermore, when the cases of head and neck cancer were limited to having developed 5 years or longer after the index event, statistical significance was seen regarding relative risk in the cannabis-disorder cohort vs the no cannabis-disorder cohort, but only for individuals with any head and neck cancer (RR, 5.00; 95% CI, 2.62-9.56); statistical significance was not seen with any subsite.

“Our research shows that people with cannabis-use disorder are up to five times more likely to develop head and neck cancers, highlighting a health risk comparable to tobacco smoking, Niels Kokot, MD, senior study author and head and neck surgeon at Keck Medicine of USC, wrote in a statement to OncLive^®. “Since cannabis is often inhaled, exposing users to carcinogens, we believed it was crucial to investigate potential associations with head and neck cancer using a large database. The key clinical implication is the established link between cannabis use and head and neck cancer, warranting further investigation into causation. As cannabis use grows more widespread, understanding these risks is crucial for making informed decisions based on these findings.”

Reference

Gallagher TJ, Chung RS, Lin ME, Kim I, Kokot NC. Cannabis use and head and neck cancer. JAMA Otolaryngol Head Neck Surg. Published August 8, 2024. doi:10.1001/jamaoto.2024.2419