Bacteria associated with gum disease and tooth loss in adults may be a pre-curser for the development of colon cancer, according to a team of scientists at the Dana-Farber Cancer Institute and the Broad Institute.

In the study published online in the journal Genome Research, the researchers found an abnormally large number of fusobacterium, a bacterium associated with the development of periodontal disease ? in nine colorectal tumor samples, pointing to the possibility the two could be associated.

Colon cancer is one of the top three deadly cancers in the United Kingdom and the US. Thin the UK, around 35,000 people are diagnosed with colon cancer, also called bowel cancer, every year and around half of them die. In the United States, 141,000 people will be diagnosed with
colon cancer each year, causing more than 49,000 deaths.

A confirmed connection between fusobacterium and the onset of colorectal cancer would mark the first time any microorganism has been found to play a role in this type of cancer, which is the second leading cause of cancer deaths in the United States.

“While more research is needed to determine the extent of any association between the two, the research suggests the bacteria could play a role,” said Bramson, D.D.S., chief dental officer for United Concordia Dental.

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“A lot of research exists associating periodontal disease, commonly known as gum disease, to a number of medical conditions such as heart disease, stroke, diabetes and premature or low birth weight infants,” said Bramson. “This study helps us continue to learn more about the overall body connection that exists between a person’s oral and overall health. Certainly, this does not suggest a causal relationship, but it further helps grow the science behind what we know about periodontal health and a person’s general health.”

The discovery was made by sequencing the DNA within nine samples of normal colon tissue and nine of colorectal cancer tissue, and validated by sequencing 95 paired DNA samples from normal colon tissue and colon cancer tissue. Analysis of the data turned up unusually large amounts of fusobacterium’s signature DNA in the tumor tissue

Lead author Matthew Meyerson, co-director of the Center for Cancer Genome Discovery at Dana-Farber and a professor of pathology at Harvard Medical School, confirmed that more reseatch was needed. “At this point, we don’t know what the connection between Fusobacterium and colon cancer might be. It may be that the bacterium is essential for cancer growth, or that cancer simply provides a hospitable environment for the bacterium. Further research is needed to see what the link is.”

Chief executive of the British Dental Health Foundation, Nigel Carter, said that this study further highlights the importance of good oral health: “This research, although at an early stage, is more evidence of the systemic links between oral and overall health. Everyone suffers from gum disease at some point in their lives, which could potentially endanger thousands of people if they persist in neglecting their oral health.”

Pancreatic cancer
Previous studies published in the Journal of the National Cancer Institute (JNCI) also reported positive associations between tooth loss or periodontitis and pancreatic cancer risk. In this study, data on periodontal disease a total of 216 patients were diagnosed with incident pancreatic cancer during 16 years of follow-up. Compared with no periodontal disease, history of periodontal disease was associated with increased pancreatic cancer risk. This study also showed that, in contrast, baseline number of natural teeth and cumulative tooth loss during follow-up were not strongly associated with pancreatic cancer. The researchers concluded that the association between periodontal disease and increased risk of pancreatic cancer may occur through plausible biologic mechanisms, but noted that confirmation of this association is necessary.

For more information
Dominique S. Michaud DS, Joshipura K, Giovannucci E, Fuchs CS. A Prospective Study of Periodontal Disease and Pancreatic Cancer in US Male Health Professionals. JNCI J Natl Cancer Inst (17 January 2007) 99 (2): 171-175. doi: 10.1093/jnci/djk021

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