LOS ANGELES, July 17, 2025 — Adults diagnosed with cannabis use disorder (CUD) face a significantly higher risk of developing benign tumors in their major salivary glands, with the elevated risk persisting for more than five years, a new retrospective study found. The parotid salivary gland appeared particularly susceptible.
Cannabis Use Linked to Fivefold Increase in Salivary Gland Tumors
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A retrospective study analyzing millions of patient records reveals a striking association between cannabis use disorder and benign salivary gland tumors.
Did cannabis use disorder contribute to a fivefold increased risk for benign tumors of major salivary glands? Yes, a new retrospective study indicates this elevated risk was observed when compared to individuals without CUD, and it persisted for over five years, notably affecting the parotid gland.
Researchers aimed to investigate whether CUD, similar to cigarette smoking, could be linked to benign gland tumors. They analyzed electronic medical records from 66 U.S. healthcare organizations between 2005 and 2025. The study compared nearly 184,000 adults with a history of hospital outpatient visits and CUD to over 6 million individuals without CUD.
To account for various health factors, including age, race, ethnicity, tobacco and nicotine use disorders, and radiation history, researchers employed propensity score matching.
Key Findings Show Significant Risk Increase
The incidence of benign tumors in any major salivary gland was 0.08% in the CUD group versus 0.02% in the non-CUD group. Similarly, parotid salivary gland tumors occurred at a rate of 0.05% in the CUD group compared to 0.01% in the control group.
The relative risk for any benign major salivary gland tumor was substantially higher in the CUD group across all assessed timeframes. The risk ratio was 5.2 for any time, 4.3 for the 0-5 year period, and 5.0 for periods of five years or longer.
For benign tumors specifically of the parotid salivary gland, the relative risk also increased following a CUD diagnosis. The risk ratios were 5.2 for any time, 4.9 for the 0-5 year period, and 3.9 for periods of five years or longer.
Implications for Clinical Practice
“The elevated relative risk of benign parotid tumors and the persistent association over time highlight potential site-specific outcomes of cannabis use,” the study’s investigators noted.
They emphasized the need for further investigation. “Future prospective research with large samples and data on cannabis dosing, method of use, and benign salivary gland neoplasm pathology is required to further assess and confirm this association,” they added.
Limitations of the study include the lack of specific cannabis dosage information and detailed histologic data on the benign salivary gland tumors. The follow-up period, while extensive, was also noted as a constraint.
The study was led by Tyler J. Gallagher, MD, of the Keck School of Medicine at the University of Southern California, Los Angeles. It was published online on July 17 in JAMA Otolaryngology-Head & Neck Surgery.
The investigators reported no relevant conflicts of interest.
