Study: Cannabis Use Not Independently Linked to Head and Neck Cancer, Unlike Alcohol and Cigarettes

The analysis, which relied on hospital data accessed through the i2b2 platform and ICD-10 codes, found that while cannabis users initially showed higher odds of both oral and oropharyngeal cancers, those associations disappeared after adjusting for key factors. The unadjusted odds ratio for oropharyngeal cancer among cannabis users was 3.12, and for oral cancer it was 2.38. These results remained significant after accounting for demographic variables such as gender, age, and race.

However, when alcohol use, cigarette smoking, and HPV vaccination status were included, the cannabis association lost statistical significance. For example, the adjusted odds ratio for oropharyngeal cancer among cannabis users dropped to 1.07, while oral cancer fell to 0.7. In contrast, alcohol use and cigarette smoking showed much stronger links, with adjusted odds ratios of 7.95 and 7.39 for oropharyngeal cancer, and 9.67 and 7.52 for oral cancer. HPV vaccination was found to have a protective effect for both cancer types.

The researchers conclude by saying “Alcohol and cigarette smoking rather than the use of cannabis may play a major role in establishing an association between cannabis use and both types of head and neck cancers.”