Oral Precancerous Lesions Raise Cancer Risk of Non-Smokers

Tobacco may not be to blame for aggressive oral cancers, a new study suggests.

Tobacco use is strongly linked to the development of oral cancers, which is why health experts advise against using cigarettes and other tobacco-based products. However, even avoiding these products may not lower the risk of certain types of cancer.

Related Coverage: Nearly Half of Cancers, Related Deaths Are Preventable

A new study published by Oral Oncology suggests that individuals with precancerous lesions who are not smokers may be more likely to develop cancer compared with smokers.

The analysis revealed that oral precancerous lesions were more than twice as likely to turn cancerous than those in smokers. Additionally, lesions in non-smokers progressed significantly faster than smoking-related lesions, according to the study.

“This is the first published study where the main focus was to examine the difference in risk of progression to oral cancer between non-smokers and smokers with oral precancerous lesions,” said lead author Leigha Rock. “While other studies have also reported a higher rate of transformation among non-smokers, we looked at multiple risk factors including genetic markers.”

Included in the study were 445 patients with oral epithelia dysplasia (OED), which are precancerous lesions. One-third of the study population were non-smokers.

“As smoking rates decline, we are seeing an increase in the proportion of these types of lesions in non-smokers,” Rock said.

OEDs on the floor of the mouth in non-smoking patients were 38 times more likely to progress to cancer compared with lesions in smokers, according to the study.

The authors also found that at both 3 and 5 years, OED progression rate was 7% and 6.5% higher among non-smokers than smokers, respectively.

These disparities in outcomes may be linked to differing causes of the lesions, according to the authors. For smokers, the lesions are most likely related to tobacco use and other environmental factors, while non-smokers may have a genetic mutation that made them more susceptible.

“Our findings show that molecular genomic markers can identify high risk lesions, regardless of risky habits like smoking, and should be an important consideration in patient management,” Rock said.

The authors said that the results stress the importance of identifying and monitoring oral lesions, especially in non-smokers. Currently, non-smokers may not be concerned over OEDs due to their smoking status, suggesting the need for additional education.

“If you see a lesion in a smoker, be worried. If you see a lesion in a non-smoker, be very worried,” Rock concluded. “Don’t assume it can’t be cancer because they’re a non-smoker; our research indicates non-smokers may be at higher risk.”