Individuals with cannabis use disorder (CUD) are over three times more likely to develop oral cancer within five years than those without the condition. The corresponding study was published in Preventive Medicine Reports.
Around 52.5 million people, or almost 20% of Americans, used cannabis at least once in 2021. Research meanwhile indicates that around 30% of those who use cannabis develop CUD. While the link between tobacco and oral cancers is well known, the risk between cannabis and the same conditions is less well defined, with epidemiological studies having reported mixed results until now.
In the current research, researchers conducted a retrospective cohort study using electronic healthcare data from California. They included data from over 45,000 patients without a prior oral cancer diagnosis and followed them for five years to see whether or not they developed oral cancer- defined as lip or tongue cancer.
Over five years, 949 or 2.1% of patients developed CUD. Meanwhile, 0.74% of those with CUD and 0.23% of those without developed oral cancer.
After adjusting for factors including age, sex, body mass index, and smoking status, the researchers found that participants with CUD were 325% more likely to develop oral cancer than those without. Meanwhile, tobacco smokers with CUD were 624% more likely to develop oral cancer than tobacco smokers without CUD.
To explain the findings, the researchers noted that cannabis smoke contains many of the same carcinogenic compounds found in tobacco. They added that studies show that cannabis condensates induce DNA damage and chromosomal aberrations in mammalian cells as well as mutations in bacterial assays.
They also wrote that tetrahydrocannabinol, the primary psychoactive compound in cannabis, has been shown to suppress immune responses, something that could inhibit immune surveillance and facilitate tumor growth.
“As cannabis becomes more widely available and socially accepted, it is critical that public health messaging and clinical guidelines reflect emerging evidence on potential harms. Clinicians should consider oral cancer screening and counseling as part of routine care for individuals with CUD, particularly those with additional risk factors,” wrote the researchers in their paper.
Sources: EurekAlert, Preventive Medicine Reports