A recent study showed an intriguing link between gum disease and pancreatic cancer. In the past, inflamed gums and tooth loss have been linked to serious health problems elsewhere in the body. Now a study is adding cancer to the list of possible problems.
The three culprits that are highlighted in the Harvard School of Public Health study are all related to periodontal disease: tissue inflammation, particularly over many years, higher levels of bacteria in the mouth and tooth loss due to gum disease.
Two previous studies had linked periodontal gum disease and pancreatic cancer. However, the studies took other risk factors into account, such as smoking and heart disease.
Smoking was found to contribute to both periodontal disease and cancer, according to studies done by the American Association of Cancer Research. While the new study has removed the smoking factor, it should not be ignored, as it is a risk factor that could also be acting as a promoter of inflammation.
The final result showed that among men who had never smoked, having periodontal disease and tooth loss in the last four years of the Harvard study periodontal disease made them 2.5 times more likely to get pancreatic cancer than those without the gum problems. This was a defining factor for the researchers, who concluded that there was a probable link between periodontal disease and pancreatic cancer.
One of the other main questions that the Harvard researchers asked was whether systematic inflammation from periodontal disease was related to pancreatic cancer. Previous studies had shown that some cases of inflammation in the body had caused high risk for developing pancreatic cancer, but they wanted to specifically study inflammation of the gums.
The results showed that 63 percent of the observed men with gum disease and bleeding were more likely to be affected by pancreatic cancer than men who do not suffer from it. It also showed that men with an earlier record of gum disease were more likely to be afflicted with cancer. The researchers analyzed 16 years of health data on more than 52,000 men.
The effect of bacteria was the next area of interest. Researchers found that if a person has gum disease, normal brushing of his teeth or chewing allowed bacteria to enter his bloodstream. The study’s lead author, Dominique Michaud, stated that people with periodontal disease have higher blood levels of C-reactive protein, an inflammatory marker that may somehow contribute to the promotion of cancer cells.
There is a high amount of bacteria in the mouths of people with periodontal disease, as well as in their intestinal systems. Bacteria in the people affected with gum disease produce a dangerous substance called nitrosamines. The majority of nitrosamines are considered to have carcinogenic properties that cause cancer in humans.
In addition, scientists from the University of Illinois at Urbana-Champaign have studied the only bacteria known to survive long-term in the human stomach. They found that it also activates an enzyme that is linked to some cancers.
Previous studies showed a relationship between cancer and tooth loss, as well cancer and gum infection that lasted longer that normal. The effects of the bacteria were added in this Harvard study. It was found that these could trigger a body-wide immune response like inflammation. Chemical signals are then released, which can result in developing tumor growth.
In order to study how important tooth loss is to pancreatic cancer, the researchers needed to form a baseline. They recorded the condition of all teeth at the beginning of the study. Then they recorded those teeth lost in the early years, mainly due to cavities. And, finally the teeth lost during the follow-up period of the study, which were mainly due to periodontal disease.
They found that the men who lost teeth to the disease during the later years of the study because of periodontal disease were more likely to get pancreatic cancer. However, tooth loss had a lesser affect than the inflamed gums did.
The researchers were not able to explain exactly how periodontal disease was linked to the cancer. While pancreatic cancer is the fourth-leading cause of cancer death in the United States, it is still relatively rare and not a lot is known about it. It affects approximately 30,000 lives a year. Pancreatic cancer has the lowest survival rate of any carcinoma.
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Study conducted by the Harvard School of Public Health, and the Dana-Farber Cancer Institute. The article was published Jan. 17, 2007, in The Journal of the National Cancer Institute; and was reported at the 2006 Frontiers in Cancer Prevention Research meeting in Boston.
Dr. Dominique Michaud and Dr. Charles Fuchs are the key authors of the study, Harvard School of Public Health, Boston.