In recent years, some of the research into causes of cancer has focused on the microenvironments where cancer grows and specific types of microorganisms as possible carcinogens.
New investigations point to a microorganism called Fusobacterium and its link to colorectal cancer, the second-leading cause of cancer deaths in the United States. Although researchers can’t say for sure whether those particular bacteria are the cause, they are pleased with the prospect that further studies might give definitive answers.
The Fusobacterium link came out of two separate studies conducted at about the same time and both published in October, 2011. One study is from the BC Cancer Agency and Simon Fraser University in Canada, and the other is from the Dana-Farber Cancer Institute and the Broad Institute in Boston. Both studies appeared online in the journal Genome Research.
According to the October 17, 2011, ScienceDaily, a confirmed connection between the genus Fusobacterium and the onset of colorectal cancer would mark the first such bacterial link regarding this kind of cancer. Down the road, it could mean finding ways to fight the bacteria and eventually learn how to prevent and treat colorectal cancer, perhaps with new vaccines or antibiotics.
The research by the two different teams involved sequencing either the DNA or studying the RNA in noncancerous colon tissue versus cancerous tissue. Fusobacterium’s signature DNA and its RNA appeared in unusually large amounts in the cancerous tissue. The next set of studies will look at the microenvironments for colorectal cancer in larger populations and in animals.
"Tumors and their surroundings contain complex mixtures of cancer cells, normal cells, and a variety of microorganisms such as bacteria and viruses," the study's senior author, Dr. Matthew Meyerson of Dana-Farber and the Broad Institute, was quoted as saying in ScienceDaily. "Over the past decade, there has been an increasing focus on the relationship between cancer cells and their 'microenvironment,' specifically on the cell-to-cell interactions that may promote cancer formation and growth."
Interestingly, Fusobacterium has previously been linked to inflammatory bowel disease, which in turn is a risk factor for colorectal cancer.
While research into the causes of colorectal cancer continues, it’s good to become acquainted with various risk factors, to make appropriate changes to your lifestyle, and to get screened. According to the American Cancer Society, risk factors include: certain types of colon polyps; a history of bowel disease; close relatives with colorectal cancer; your race or ethnic background; lack of exercise; being overweight; smoking; and alcohol use. The website of the American Cancer Society at www.cancer.org can provide details.
“Possible Link Between Bacterium and Colon Cancer Discovered.” ScienceDaily. Web. 18 October 2011. http://www.sciencedaily.com/releases/2011/10/111017184651.htm
“First Infectious Agent Associated with Colon Cancer Identified.” ScienceDaily. Web. 18 October 2011. http://www.sciencedaily.com/releases/2011/10/111017171502.htm
“What causes colorectal cancer?” American Cancer Society: Colorectal Cancer Overview. Web. 18 October 2011. http://www.cancer.org/Cancer/ColonandRectumCancer/OverviewGuide/colorectal-cancer-overview-what-causes
Reviewed October 19, 2011
by Michele Blacksberg RN
Edited by Jody Smith