Dental caries may prevent oral cancer
BUFFALO, N.Y., USA: Researchers from the U.S. have found that people with more dental cavities may be significantly less likely to be diagnosed with head and neck squamous cell carcinoma, i.e., cancer of the lip, oral cavity, pharynx and larynx. The findings suggest that certain bacteria that cause dental decay may have beneficial effects on certain types of cancer.
In order to test the association between dental caries and head and neck squamous cell carcinoma, researchers from the University at Buffalo examined the oral cavities of 399 patients diagnosed with primary head and neck squamous cell carcinoma between 1999 and 2007, and 221 healthy controls.
They observed that cancer patients had a significantly lower mean number of teeth with caries, crowns, endodontic treatment and fillings. However, they had more missing teeth compared with controls. After adjusting for age, sex, marital status, smoking status and alcohol use, the researchers found that the prevalence of head and neck squamous cell carcinoma was lower among participants with prevalent dental caries and more crowns.
Although the mechanism underling this inverse association between head and neck squamous cell carcinoma and dental caries is not fully understood by the scientists, the study suggests that lactic acid bacteria, which demineralize tooth structures, and their associated immune response may have a positive effect on the cancer cells.
According to the Centers for Disease Control and Prevention, dental caries is the most common chronic disease among children aged 6 to 11 years and adolescents aged 12 to 19 years in the U.S. It also affects the majority of adults, with 9 in 10 over 20 having some degree of tooth-root decay. More than 30,000 new cases of cancer of the oral cavity and pharynx are diagnosed each year.
The study, titled "Dental Caries and Head and Neck Cancers," was published online on Sept. 12 in the JAMA Otolaryngology — Head and Neck Surgery journal.