WASHINGTON, Jan. 16 (UPI) -- A large, prospective study has again identified a link between periodontal disease and a higher risk of pancreatic cancer, the fourth-leading cause of cancer death in the United States, experts reported Tuesday.
Researchers found men with periodontal, or gum, disease had a 63 percent higher risk of getting pancreatic cancer as compared to those without the condition.
"It's been a real struggle to understand the risk factors for a disease which is highly fatal and poorly understood," said senior author Dr. Charles Fuchs, a gastrointestinal oncologist at the Dana-Farber Cancer Institute in Boston.
Fuchs and colleagues at the Harvard School of Public Health gathered data from a group of 51,529 male health professionals -- mostly white dentists -- who were aged 40 to 75 years. The participants completed a questionnaire about their health every two years from 1986 to 2002. Of the group, 216 patients developed pancreatic cancer and 67 got periodontal disease. The researchers used statistical analyses to evaluate the risk of pancreatic cancer.
This study, which will be published Wednesday in the Journal of the National Cancer Institute, goes beyond the scope of previous studies by offering more detailed data, as well as drawing from a huge sample size, Fuchs said.
Two recent, smaller studies found the same connection between periodontal disease and pancreatic cancer, but experts agree they were not as reliable because some of the participants were smokers. Smoking is one of a few known risk factors for pancreatic cancer.
The researchers made sure smoking did not influence their results; in fact, eliminating smokers from their analyses revealed an even stronger association.
People who have severe periodontal disease or gingivitis also often have elevated levels of C-reactive protein in their blood, which is a marker of chronic inflammation.
This association motivated the team to investigate whether inflammation plays a role in the link between periodontal disease and pancreatic cancer.
Inflammation can cause cell mutation and proliferation, which in turn can promote tumor development. Persistent inflammation also seems to inhibit the body to allow cells to die -- a process called programmed cell death -- and that may lead to cancer. Chronic pancreatitis has also been associated with an elevated risk for cancer of the pancreas.
The pancreas is a digestive organ responsible for producing hormones and digestive enzymes. Pancreatic cancer affects around 33,000 people each year, and almost that many die each year from the disease.
Scientists know little about the cancer, particularly because people who get it usually die within months of diagnosis. It's also hard to detect and overwhelmingly resistant to treatment.
Pancreatic cancer is sometimes familial; it can be caused by cigarette smoking; and it often develops in African-Americans, particularly in Louisiana. Evidence also suggests type 2 diabetes, obesity and resistance to insulin can raise a person's risk.
Recent research has found periodontal disease may raise the risk for coronary heart disease -- a condition also driven by chronic inflammation.
The study was limited by its reliance on the participants to report their own health diagnoses. Even so, since most of the participants were dentists, Fuchs said, he expects most of the data is accurate. Because the study only observed phenomena, it is too early to draw conclusions about whether periodontal disease causes pancreatic cancer.
And although the study only looked at men, Fuchs and colleagues plan to focus on women in their upcoming research.
The research points to oral health as one more aspect of a healthy lifestyle that Americans, especially seniors, should follow, said Dr. Len Lichtenfeld, deputy chief medical officer for the American Cancer Society.
As research has begun to show, "a healthy mouth may be a healthy body as well," Lichtenfeld said.
