The presence of 2 species of bacteria, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans, which are both linked to periodontal disease in the mouths of healthy individuals, was associated with an elevated risk for developing pancreatic cancer, research presented at the American Academy for Cancer Research (AACR) Annual Meeting 2016 has shown.1
“Previous studies have shown that indicators of poor oral health, including a history of periodontal disease and lots of missing teeth, are associated with an increased risk of pancreatic cancer,” said Jiyoung Ahn, PhD, associate professor of population health and associate director of population sciences at the Laura and Isaac Perlmutter Cancer Center at NYU Langone Medical Center in New York, NY.
“To test the idea that this association is driven by species of oral bacteria linked to periodontal disease, we first needed to determine whether these bacteria are even associated with pancreatic cancer risk.”
For the study, researchers analyzed oral wash samples from 361 patients who subsequently developed pancreatic cancer and from 371 matched control who were participants of the Cancer Prevention Study II or the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Genomic technologies were used to create a profile of the bacterial species present in each sample.
Results showed that the presence of P. gingivalis in oral wash samples was associated with a 59% increased risk of pancreatic cancer (OR, 1.59; 95% CI, 1.15-2.20), while the presence of A. actinomycetemcomitans was associated with a 119% increased risk (OR, 2.19; 95% CI, 1.15-4.15).
In contrast, researchers found that greater relative abundance of phylum Fusobacteria was associated with decreased pancreatic risk (OR per percent increase of abundance, 0.92; 95% CI, 0.87-0.98).
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“We found that Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans, two species of bacteria linked to periodontal disease, were associated with a more than 50 percent increased risk of pancreatic cancer,” Dr Ahn said. “These data do not show a causal relationship, but they are the first steps in understanding a potential new risk factor for pancreatic cancer, which is vital if we are to develop new approaches for pancreatic cancer prevention and early detection in the future.”
The investigators note, however, that this study included predominantly non-Hispanic white and healthy patients, thereby limited its generalizability to the whole population.
- Fan X, Alekseyenko AV, Wu J, et al. Human oral microbiome and prospective risk for pancreatic cancer: a population based, nested case control study. Oral presentation at: AACR Annual Meeting 2016; April 16-20, 2016; New Orleans, LA.