Oral bacteria may help spot pancreatic cancer: study

The presence of certain bacteria in the mouth may point to increased risk for pancreatic cancer and enable earlier, more precise treatment, a new study has found.

Pancreatic cancer patients are known to be susceptible to gum disease, cavities and poor oral health in general, said researchers at NYU Langone Medical Centre in the US.

That vulnerability led the researchers to search for direct links between the makeup of bacteria driving oral disease and subsequent development of pancreatic cancer, a disease that often escapes early diagnosis and causes 40,000 deaths in US annually, researchers said.

“Our study offers the first direct evidence that specific changes in the microbial mix in the mouth - the oral microbiome - represent a likely risk factor for pancreatic cancer along with older age, male gender, smoking, African-American race, and a family history of the disease,” said senior investigator and epidemiologist Jiyoung Ahn.

Researchers found that men and women whose oral microbiomes included Porphyromonas gingivalis had an overall 59 per cent greater risk of developing pancreatic cancer than those whose microbiomes did not contain the bacterium.

Similarly, oral microbiomes containing Aggregatibacter actinomycetemcomitans were at least 50 per cent more likely overall to develop the disease.

Doctoral student and study lead investigator XiaoZhou Fan said both types of bacteria have been tied in the past to such diseases as periodontitis, or inflammation of the gums.

“These bacterial changes in the mouth could potentially show us who is most at risk of developing pancreatic cancer,” said Ahn, an associate professor at NYU Langone and associate director of population sciences at the Perlmutter Cancer Centre.

In another study published last month, Ahn and her colleagues showed that cigarette smoking was linked to dramatic, although reversible, changes in the amount and mix of bacteria in the oral microbiome.

Further research is needed to determine if there is any cause-and-effect relationship, or how or whether such smoking-related changes alter the immune system or otherwise trigger cancer-causing activities in the pancreas, researchers said.

For the new study, researchers compared bacterial contents in mouthwash samples from 361 American men and women who developed pancreatic cancer with samples from 371 people of similar age, gender and ethnic origin who did not.

Mouthwash samples were obtained at the beginning of each investigation, after which participants were monitored for nearly a decade to determine who got cancer.