Could dentists stop stomach cancer?

December 14, 2017

New research suggests a link between periodontitis and stomach cancer.

In 2016, the CDC estimated that 26,370 cases of stomach cancer would be diagnosed and result in 10,703 deaths. Dentists could help change that number, according to new research.

A new study, conducted at the NYU College of Dentistry and published in the Journal of Periodontology, found that the bacteria responsible for periodontitis are also associated with precancerous lesions in the stomach. These lesions, including chronic atrophic gastritis, intestinal metaplasia and dysplasia, can predict stomach cancer.

“Our study reinforces earlier findings that poor oral health is associated with an increased risk of precancerous lesions of stomach cancer,” says Yihong Li, DDS, MPH, DrPH, professor of basic science and craniofacial biology at NYU Dentistry and the study’s corresponding author.

Researchers were already aware that a variety of factors, like H. pylori colonization, cigarette smoking, and eating salt and preserved foods can contribute to stomach cancer, but many new cancer patients did not have these risk factors. Researchers hypothesized that the bacteria responsible for periodontitis are also responsible for chronic systemic inflammation that can in turn cause stomach cancer.

To conduct the study, researchers examined a group of 105 patients who received an upper endoscopy. Out of that group, 35 had precancerous lesions, while the remaining 70 did not and were used as a control group. Researchers performed full-mouth examinations to assess periodontal conditions - including the colonization of several pathogens and the amount of oral microbial diversity.

Compared with the control group, the 35 patients had higher levels of bleeding when probed (31.5 percent versus 22.4 percent), higher levels of two pathogens (T. denticola and A. actinomycetemcomitans) and less bacterial diversity in their saliva. Further analysis, which took into consideration sociodemographic factors, oral health behaviors and periodontal assessments found another bacterium (T. denticola) to be responsible, along with poor flossing habits and lower bacterial diversity in dental plaque.

All of this led researchers to conclude that higher levels of the bacteria responsible for periodontitis, along with lower bacterial diversity levels in the mouth, could contribute to a higher risk of a patient developing precancerous lesions.

“Based on our findings, treatment for chronic periodontal disease and control of periodontal pathogen infections should be included in future strategies for preventing stomach cancer,” says Li.

The full study, “Chronic Periodontal Disease, Periodontal Pathogen Colonization, and Increased Risk of Precancerous Gastric Lesions” can be found at the Journal of Periodontology.