Researchers from Harvard T.H. Chan School of Public Health in Boston found that a history of gum (periodontal) disease is linked to an increased risk of gastric cancer and esophageal cancer. This risk appears to be higher among people who had previously lost teeth.
Signs of gum disease
- Bleeding gums when brushing or flossing
- Red, swollen or tender gums
- Gums that pull away from the teeth
- Teeth that seem to be loose or moving away from one another
- Pus between gums and teeth
- Sores in the mouth
- Persistent bad breath
- Change in the way the teeth fit together when you bite
- Change in the way dentures fit
The researchers examined 98,459 women from the Nurses’ Health Study (1992 to 2014) and 49,685 men from the Health Professionals Follow-up Study (1988 to 2016) to establish the link.
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The results of the study:
- During the 22 to 28 years of follow up, there were 238 cases of gastric cancer and 199 case of esophageal cancer.
- A history of gum disease was associated with a 52% and 43% heightened risk of gastric cancer and esophageal cancer respectively.
- Compared to those with no tooth loss, the risks of esophageal and gastric cancer for those who lost two or more teeth were also modestly higher – 42% and 33%, respectively.
- Those with a history of gum disease, no tooth loss and losing one or more teeth were equally associated with a 59% increased risk of esophageal cancer compared to those without history of gum disease and tooth loss.
What are the possible reasons for an association between oral bacteria and esophageal and gastric cancer?
- Evidence from other studies suggest that Tannerella forsythia and Porphyromonas gingivalis (members of the ‘red complex’ of periodontal pathogens) were associated with the presence or risk of esophageal cancer.
- Poor oral hygiene and gum disease could promote the formation of endogenous nitrosamines known to cause gastric cancer through nitrate-reducing bacteria.
Published on BMJ.com, the researchers maintained: This was an observational study, so no firm conclusions can be drawn about cause and effect, and the researchers cannot rule out the possibility that some of the observed risk may be due to other unmeasured (confounding) factors.
What are the possible reasons for an association between oral bacteria and esophageal and gastric cancer?
“Together, these data support the importance of oral microbiome in esophageal and gastric cancer. Further prospective studies that directly assess oral microbiome are warranted to identify specific oral bacteria responsible for this relationship. The additional findings may serve as readily accessible, non-invasive biomarkers and help identify individuals at high risk for these cancers.”
