Gum disease may raise risk of oesophageal and gastric cancer
US researchers have found that People with history of gum disease appear to have higher risk of developing oesophageal and gastric cancer.
People who have periodontal (gum) disease may have a higher risk of developing some forms of cancer, suggests a letter published in the journal Gut detailing a prospective study.
Previous
findings on the relationship of periodontal disease and tooth loss with
oesophageal and gastric cancer have been inconsistent.
Therefore, a team of researchers from Harvard T.H. Chan School of Public
Health, in Boston, USA, carried out a study of data on patients over decades of
follow up.
They
examined the association of history of periodontal disease and tooth loss with
the risk of oesophageal 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 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
oesophageal cancer and 238 cases of gastric cancer.
A history
of periodontal disease was associated with a 43% and 52% increased risk of
oesophageal cancer and gastric cancer, respectively.
Compared to people with no tooth loss, the risks of oesophageal and gastric
cancer for those who lost two or more teeth were also modestly higher – 42% and
33%, respectively.
In
addition, among individuals with a history of periodontal disease, no tooth
loss and losing one or more teeth were equally associated with a 59% increased
risk of oesophageal cancer compared to those with no history of periodontal
disease and no tooth loss.
Similarly, the same group of individuals had 50% and 68% greater risk of
gastric cancer, respectively.
The authors point to possible reasons for an association between oral bacteria (oral microbiota) and oesophageal and gastric cancer, with evidence from other studies suggesting that tannerella forsythia and porphyromonas gingivalis – members of the 'red complex' of periodontal pathogens – were associated with the presence or risk of oesophageal cancer.
Another
possible reason is that poor oral hygiene and periodontal disease could promote
the formation of endogenous nitrosamines known to cause gastric cancer through
nitrate-reducing bacteria.
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.