Gum disease can increase the risk of esophageal and stomach cancer
This risk is higher in those with tooth loss, according to a study.
People who have periodontal (gum) disease may be at increased risk of developing some forms of cancer, suggests a letter published in the journal “Gut” detailing a prospective study.
American researchers found that a history of periodontal disease appeared to be associated with an increased risk of esophageal cancer and gastric (stomach) cancer, and this risk was also higher among people who had previously lost teeth.
Since previous research on the relationship of periodontal disease and tooth loss to esophageal and gastric cancer had been inconsistent, a team of Harvard T.H. Chan School of Public Health in Boston (USA) conducted a study of patient data over decades of follow-up.
They examined the association of a history of periodontal disease and tooth loss with risk of esophageal and gastric cancer in 98,459 women from the Nurses’ Health Study (1992-2014) and 49,685 men from the Health Professionals Follow-up Study (1988- 2016).
Dental measures, demographics, lifestyle, and diet were assessed using follow-up questionnaires, and the self-reported cancer diagnosis was confirmed after reviewing medical records. The results showed that during 22-28 years of follow-up, there were 199 cases of esophageal cancer and 238 cases of gastric cancer.
Having a history of periodontal disease was associated with a 43% and 52% increased risk of esophageal cancer and gastric cancer, respectively. Compared to people without tooth loss, esophageal and gastric cancer risks for those who lost two or more teeth were also moderately higher: 42% and 33%, respectively.
In addition, having a history of periodontal disease, without tooth loss and with the loss of one or more teeth, was also associated with a 59% increased risk of esophageal cancer, compared to those without a history of periodontal disease and without tooth loss.
The authors point to possible reasons for an association between oral bacteria (oral microbiota) and esophageal and gastric cancer, with evidence from other studies suggesting that tannerella forsythia and porphyromonas gingivalis, members of the “red complex” of pathogens periodontals, were associated with the presence or risk of esophageal cancer.
Another possible reason is that poor oral hygiene and periodontal disease could promote the formation of endogenous nitrosamines that are known to cause gastric cancer through nitrate-reducing bacteria.
This was an observational study, so no firm conclusions about cause and effect can be drawn, and the researchers cannot rule out the possibility that some of the observed risk may be due to other unmeasured factors (confounders).
Together, these data support the importance of the oral microbiome in esophageal and gastric cancer. Further prospective studies that directly assess the oral microbiome to identify the specific oral bacteria responsible for this relationship are warranted. The additional findings may be used to help identify people at high risk for these cancers, ”the authors conclude.