Bacterial causes of colon cancer shed light on new methods for prevention and treatment
Kathryn E. Vinson, MS, CCRC
Cancer is a terrifying word, regardless of what body system it strikes, or how old we are when it is diagnosed. While all types of cancer leave emotional scars after the battle has been waged, many types leave lasting physical reminders of the war that has been fought. One of these diseases, colorectal cancer, comes with the very real possibility of lasting lifestyle changes in the form of colostomy bags and special diets.
The American Cancer Society projects 97,220 new cases of colon cancer and 43,030 new cases of rectal cancer in the United States for 2018. They further report that deaths from this disease group have been dropping over the last several decades, thanks in large part to increased rates of screening for these conditions. Five-year survival rates range from 92% for stage 1 diagnoses to only 12% for stage IV disease. Clearly, early detection is key to survival. Screenings typically consist of colonoscopies to visually inspect the colon and rectum for polyps and diseased lesions. The frequency of these tests depends upon age, previous colonoscopy results (if any), and concerning symptoms such as blood in the stools. For those at “average” risk for the development of disease, the American Cancer Society recommends regular screening begin at age 45 via either tests for blood in the stool of by colonoscopy. We urge you to consult with your physician about your risk level, and a screening schedule.
But what if there was a way to predict who is more likely to be afflicted by colorectal cancer? What if the findings on a colonoscopy went beyond a visual examination or pathology on a polyp? Researchers led by a team from the Johns Hopkins Bloomberg-Kimmel Institute for Cancer Immunotherapy have recently found evidence of two different bacteria that may play a significant role in the development of both hereditary and non-hereditary colon cancers.
What they found
The scientists built upon previous research that showed certain bacteria were seen to invade the mucous membrane of patients with both inherited and non-inherited colon cancers. The two bacteria identified, Bacteroides fragilis and Escherichia coli, were found to work together to produce a biofilm next to the epithelial layer in the colon wall. Under these biofilms, the bacteria are able to make a comfortable home, where they have everything they need to proliferate. Once established, the B. fragilis produces a toxin that “triggers certain oncogenic, or cancer-promoting, pathways… The E. coli strains produced a substance called colibactin, which causes DNA mutations,” (Science Daily, 2018). These two substances create a “perfect storm” for the formation of tumors. Further, the E. coli strain, known as ETBF, activates an inflammatory response known as IL-17. Interestingly, in mice that had the IL-17 gene removed (and therefore the IL-17 protein could not be produced), colon tumors did not form, even in the presence of the two bacteria.
What it means for patients
While this research is still new, it offers a lot of hope to patients for the future. The scientists feel that by identifying these bacteria, they will have a new tool in their arsenal for early detection. People with a family history of colorectal cancers may be able to be screened for these bacteria, as well as adding an assay to routine colonoscopies to identify this deadly combination. They also hope that this identification will enable doctors to create immunotherapies and vaccines that can target these bacteria, stopping the cancerous process before it begins. The possibility of even using certain probiotics has been put forth!
If you or a loved one have been diagnosed with this disease, we urge you to reach out to others that have fought this battle. A wide variety of Colorectal Cancer Support Groups and Closed Facebook Cancer Groups can offer financial, moral, transportation and other assistance for patients and caregivers alike. Also, take a look at our pages dedicated to Cancer Products and Cancer Gifts. These products and gifts specially designed for cancer patients can mean the world to a warrior.
As always, much love, abundant blessings, and many prayers to all of the cancer warriors and their families.