New research links gum disease to pancreatic cancer risk

A new study assessed the relationship between poor dental health and pancreatic cancer risk based on a nationwide dental health registry in Sweden.

Led by Jingru Yu, researchers from the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden, examined information of exposures – dental caries, root canal infection, mild inflammation, and periodontitis; the number of teeth – ascertained from the Swedish Dental Health Register, and occurrence of pancreatic cancer, identified from both cancer and cause of death registries. 

Pancreatic cases expected to rise due to aging populations

They said the study results, published in the British Journal of Cancer, confirmed the association, suggesting the need for further studies on underlying mechanisms.

“Although the incidence of pancreatic cancer remains low,” the authors wrote, “the number of new cases and of deaths from pancreatic cancer are predicted to increase regionally and globally due to aging populations.”

Past evidence “not always consistent”

Established risk factors, including old age, male sex, chronic pancreatitis, diabetes, obesity, tobacco smoking, and family history of pancreatic cancer, only help to explain a fraction of pancreatic cancer cases, they added. 

“To date, the evidence for the link between poor dental health and pancreatic cancer risk is not always consistent, partly due to variations in study population, exposure measurement, and/or selection on adjusted confounding factors, and a lack of statistical power,” they added.

“Consequently, we aimed to quantify the association between poor dental health, in particular inflammation related oral disorders, and the risk of pancreatic cancer based on the nationwide Dental Health Register in Sweden. 

“This registry provides continuous and good quality monitoring of dental health conditions of the vast majority of Swedish adult population.”

Root canal infection potential risk factor

Over 10,000 pancreatic cancers were identified during an average period of 7.2 years. In the <50 age group, a higher risk of pancreatic cancer was observed in individuals with root canal infection, mild inflammation, and periodontitis  as compared with the healthy group. 

In the 50–70 age group, only the subgroup with periodontitis was observed to have had an excess risk. No positive association with statistical significance was observed in the 70+ age group, while individuals with fewer teeth tended to have a higher risk in all age groups.

“In this nationwide Swedish registry-based cohort study in Sweden, we confirm that periodontitis increases the risk of pancreatic cancer by 20–56% in adults under 70 years as compared with the dentally healthy individuals,” the authors wrote.

“Our results also provide new evidence that root canal infection appears to increase the risk of pancreatic cancer, with risk in individuals younger than 50 years increased by up to 58%, similar to periodontitis. To our knowledge, this fact has not been reported previously. Similarly, individuals with fewer teeth tended to have an excess risk of pancreatic cancer.”

Read the full article: Poor dental health and risk of pancreatic cancer: a nationwide registry-based cohort study in Sweden, 2009–2016.