A link to pancreatic cancer

It’s amazing how many different varieties of bacteria there are in the oral cavity. Some of them are very dangerous and pathogenic and may have more implications in other diseases than we now know. Last month we looked at how the bacteria Fusobacterium nucleatum (F. nucleatum) is closely related with colorectal cancer. Several studies have linked them together and the bacteria is found in many rectal cancer tumors. This month, I want to look into another type of cancer and another link with a periodontal disease bacteria—pancreatic cancer and its link with Porphyromonas gingivalis (P. gingivalis) and Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans).

Let’s quickly review a few studies that have discussed their link. A study by Julie Jacob found that more than 50% of patients who had pancreatic cancer also had a high percentage of the two pathogenic periodontal bacteria in their oral cavities, P. gingivalis and A. actinomycetemcomitans. “More than 50,000 people will be diagnosed with pancreatic cancer this year.” Researchers found that the people who had these two bacteria in their mouths had a greater chance of developing pancreatic cancer. This gives researchers another marker to investigate and study. The researchers looked at why this occurs and hypothesized that the “oral bacteria dysbiosis” is a main reason.1

A study by Harvard School of Public Health looked at more than 51,000 male health professionals for more than 16 years. “After adjusting for age, smoking history, diabetes, obesity, diet, and other potentially confounding variables, the researchers concluded that men with a history of periodontal disease had a 63% increased risk of pancreatic cancer compared to men without a history of periodontal disease.”2

“For years we thought that periodontal disease was simply a localized infection of the gums, but more evidence is showing that it can potentially be linked to a host of systemic conditions.”3 Although these studies do not prove that one causes the other, they do indicate strong connections between the two, and we can conclude that there is a relationship there.

A Boston-based periodontist, Terrence J. Griffin, DMD, president of the American Academy of Periodontology, states, “There has been some significant work that, to me at least, has been pretty astounding in terms of its potential link to an increased risk of pancreatic cancer.”3 Dr. Griffin stresses that more research needs to be done, and although the links between periodontal disease and pancreatic cancer have not been established as causal, periodontal disease has strong connections with many illnesses, including heart disease and diabetes.

Chang et al. conducted a research study that showed, “Periodontal disease was positively associated with pancreatic cancer risk (hazard ratio [HR], 1.55; 95% confidence interval [CI], 1.02-2.33). This positive association occurred predominantly among those aged 65 years or older.”4

“Inflammation may enhance cellular proliferation and mutagenesis, reduce adaptation to oxidative stress, promote angiogenesis, inhibit apoptosis, and increase secretion of inflammatory mediators. Serum levels of C-reactive protein and other biomarkers of systemic inflammation are consistently higher in individuals with periodontal disease than in those who have no periodontal disease.” The connection with the inflammatory response is the main connection that needs to be studied further.5

References

1. Jacob JA. Study links periodontal bacteria to pancreatic cancer risk. JAMA. 2016;315:2653-2654.

2. Periodontal disease, cancer may be linked in men. Colgate website. https://www.colgate.com/en-us/oral-health/conditions/gum-disease/ada-01-periodontal-disease. Published 2018. Accessed June 25, 2018.

3. Periodontal disease and pancreatic cancer? Let’s Win website. http://letswinpc.org/promising-science/2017/05/26/periodontal-disease-pancreatic-cancer/. Published May 26, 2017. Accessed June 25, 2018.

4. Chang JS, Tsai CR, Chen LT, Shan YS. Investigating the association between periodontal disease and risk of pancreatic cancer. Pancreas. 2016;45(1):134-41.

5. Michaud DS, Joshipura K, Giovannucci E, Fuchs CS. A prospective study of periodontal disease and pancreatic cancer in US male health professionals. J Natl Cancer Inst. 2007;99(2):171–175.