TUESDAY, Jan. 16 (HealthDay News) -- Having periodontal or gum disease may boost the risk of getting pancreatic cancer, according to new research from Harvard Medical School involving more than 51,000 men.

"Men who had reported periodontal disease had a 64 percent higher risk of pancreatic cancer [or were 1.6 times more likely to get it] compared to those who didn't have periodontal disease," said the study's lead author, Dominique S. Michaud.

The study provides the first strong evidence that gum disease may increase pancreatic cancer risk, added Michaud, an assistant professor of epidemiology at the Harvard School of Public Health in Boston.

Her team published the findings in the Jan. 17 issue of the Journal of the National Cancer Institute.

Two previous studies have uncovered a link between tooth loss or gum inflammation and pancreatic cancer, Michaud said. But one included all smokers and the other did not control for smoking, known to boost the risk of pancreatic cancer, in the analysis.

The pancreas, a gland behind the stomach, makes pancreatic juice, which helps break down fats and proteins in foods. The gland also produces the hormone insulin, which helps regulate blood sugar.

In their 16-year study, Michaud and her colleagues followed 51,529 men who participated in the Health Professional Follow-Up Study, which began in 1986. The researchers controlled for the effects of smoking.

"Our study was a prospective study of health professionals," Michaud said. "Not MDs, but dentists, podiatrists, veterinarians."

They also calculated the risk of pancreatic cancer among smokers and nonsmokers.

"Among men who never smoked, having periodontal disease led to them being twice as likely to get pancreatic cancer," Michaud said. That helped convince the researchers that periodontal disease and pancreatic cancer were linked.

The mechanism behind the link isn't known, Michaud said. And while her team found an association, it is not a proven cause-and-effect relationship.

One possible explanation is that inflammation from gum disease may somehow promote pancreatic cancer.

"People with periodontal disease have higher levels of blood levels of C-reactive protein, an inflammatory marker that has been associated with heart disease," Michaud said. "Periodontal disease is also linked to heart disease in some studies." The inflammation may somehow contribute to the promotion of cancer cells, she added.

The men in the study had severe gum disease, the type that can lead to tooth loss, she noted.

Dr. Eva Schernhammer, an assistant professor of medicine at Harvard Medical School who was not involved in the study, said the results were intriguing.

"Pancreatic cancer is one of those diseases we don't know much about," she said. "Once you get it, the survival is very low."

This research "confirms that inflammation may play an important role in pancreatic cancer," she said.

According to Michaud, the findings should also "give consumers one more reason to really take care of their teeth and their oral health. I think that's really the message, even though we aren't sure this is a causal association."

Even so, she added, "people with severe periodontal disease shouldn't be worrying they are going to get pancreatic cancer. It is a horrible disease, but it is rare."

According to the American Cancer Society, 33,730 Americans got pancreatic cancer in 2006 and more than 32,000 died from it.

More information

To learn more about pancreatic cancer, visit the American Cancer Society.