A recent study has found that daily use of marijuana for years may increase the risk of head and neck cancers by 3.5 to 5 percent.
The research — published on Thursday in JAMA Otolaryngology-Head & Neck Surgery — analysed a database of four million electronic health records from April 2004 to April 2024.
According to Niels Kokot, senior study author and professor of clinical otolaryngology-head and neck surgery at the Keck School of Medicine at the University of Southern California (USC) in Los Angeles, there were over 116,000 diagnoses of cannabis use disorder among people with head and neck cancers.
The analysis found that the diagnosis were based on self-reported drug use. It indicates the patient spoke with a healthcare clinician about how frequently they used cannabis and how it affected them.
Cannabis use disorder occurs when a person exhibits two or more symptoms, such as a desire for cannabis, the use of marijuana despite the fact that it causes issues in life, withdrawal, and inability to quit, among others.
According to Kokot, heavy cannabis users have a 3.5 to 5 times higher risk of developing head and neck cancer compared to non-users.
Head and neck malignancies affect the oral and nasal canals, pharynx, larynx, salivary glands, and thyroid.
Kokot stated that he and his team used patient data from 64 health institutions in the United States.
“Our research shows that people who use cannabis, particularly those with a cannabis use disorder, are significantly more likely to develop head and neck cancers compared to those who do not use cannabis,” he said.
“This is one of the first studies — and the largest that we know of to date — to associate head and neck cancer with cannabis use.
“The detection of this risk factor is important because head and neck cancer may be preventable once people know which behaviors increase their risk.”
The researchers said the concern lies with the chemical in marijuana called Tetrahydrocannabinol which can fasten the growth of cancer tumors.
“Part of the research we have already published shows that THC or THC-like compounds can certainly accelerate tumor growth,” Joseph Califano, the study co-author added.
“We also have some data to show that cannabinoids enhance the growth of HPV-related throat cancers.”
The study, however, found no association between the occasional recreational use of marijuana and head and neck cancer.
