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Posted in Our Blog on April 12, 2024
A new strain of bacteria discovered in colon cancer patient samples reveals a novel bacteria may contribute to colon cancer, says researchers at the Fred Hutchinson Cancer Center in Seattle, Washington.
These bacteria, found primarily at the other end of the digestive system, appear to play a role in cancer treatment failures.
Colon cancer cases are on the rise. Particularly in younger people.
It is the second-leading cause of cancer deaths in the United States, with an estimated death toll of more than 53,000 in America in 2024. And rates are rising.
According to reports, the number of people under 55 years old diagnosed with colon cancer almost doubled between 1995 and 2019. Unfortunately, these cases are often diagnosed too late, when the cancer is in more aggressive stages.
“Colorectal cancer is very treatable when caught early, but the cases in younger people are increasing and we don’t know why,” said Dr. Flavio Rocha, a surgical oncologist and physician in chief at the Oregon Health & Science University’s Knight Cancer Institute.
While the study does not address the cause of this cancer directly, it does pose a theory for why elevated levels of this bacterium are found in young colorectal cancer samples. Data suggests that these bacteria may contribute to colon cancer and remission outcomes.
What is the bacterium in question?
Fusobacterium nucleatum, a bacteria usually only found in the mouth, was found in 50% of the tumors tested in the study. This bacterium is more commonly linked to gum disease and plaque buildup; however, scientists have suspected a link between these bacteria and colorectal cancer growth for almost a decade.
One thing that does have them puzzled, is how it withstands the journey through the entire digestive system and can invade tumor cells in parts of the body this type of bacteria doesn’t usually live or survive.
In depth studies of these bacteria revealed the presence of two distinct subspecies. One subspecies of Fusobacterium nucleatum bacteria may contribute to colon cancer by helping it evade cancer-fighting drugs.
This bacterium appears to shield the colorectal tumors from cancer treatment. One scientist described it as, “It acts like a cloak.”
This bacterium appears to shield the colorectal tumors from cancer treatment.
The body’s immune system uses certain immune cells called T-cells to keep abnormal cells in check. But in the case of this subspecies of Fusobacterium nucleatum, another type of immune cell is pulled inside the tumor with it that allows the tumor to escape the T-cells notice.
In addition to identifying these bacteria in 50% of tumor samples, the bacteria was also found in stool samples at more elevated amounts, compared to health participant stool samples.
Colorectal Cancer patients with high levels of Fusobacterium nucleatum in stool samples have a far worse prognosis. These patients not only respond poorly to chemotherapy, but also have an increased risk of relapse.
With data revealing a link between Fusobacterium nucleatum and colorectal cancer, additional research on how these bacteria may contribute to colorectal cancer and other questions is necessary.
Preliminary research suggests that Fusobacterium nucleatum may actually be responsible for colorectal tumors in the first place.
When researchers transplanted this subspecies into mice, precancerous polyps appeared to form. These polyps are the first warning sign doctors look for when screening for colorectal cancer. This causation theory has not been proven in humans at this time. However, research on this topic is likely taking place.
Additional research on how this mouth bacteria can make its way through the digestive system, surviving a toxic dose of stomach acid, is also ongoing. However, researchers may have already found clues to point them in the right direction. This type of subspecies of Fusobacterium nucleatum changes key characteristics of the bacterium. This includes its ability to invade tumors and interactions with the immune system’s T-cells. These mutations may also contribute to its hardiness to travel and survive the digestive tract.
Scientists are also considering treatment protocols that involve antibiotic treatment to help clear these bacteria prior to chemotherapy. In fact, antibiotic treatment specially targeted to Fusobacterium nucleatum are slated for clinical trials soon.
Since Fusobacterium nucleatum has already proven effective at entering tumors, scientists are working on ways to harness these bacteria for treatment instead of allowing the tumors to evade treatment. Scientists can work towards genetically modifying the bacteria to carry cancer-fighting drugs directly into the tumors.
With the presence of Fusobacterium nucleatum as a potential screening method, this approach may play a bigger role in new screening opportunities. Stool samples, and even mouth swabs, may be used to identify the presence of this subspecies. The presence of this bacteria could serve as an indication that a patient is at higher risk for aggressive colon cancer.
More research is likely ongoing for using targeted antibiotics as a preventative measure for those at higher risk of colorectal cancer. A family history, previous cancer, and presence of Fusobacterium nucleatum in the mouth may all be risk factors that can warrant use of this targeted antibiotic. A targeted antibiotic would address only the subspecies of Fusobacterium nucleatum, without wiping out all bacteria in the mouth.
Whether diagnostic, preventative, or in treatment, understanding how these bacteria may contribute to colon cancer could save lives.
More research is needed to create technology to make this all happen and better understand this strange novel bacterium.
If you’d like to know more about food safety topics in the news, like New Bacteria Strain May Contribute to Colon Cancer Treatment Failure, check out the Make Food Safe Blog. We regularly update trending topics, foodborne infections in the news, recalls, and more! Stay tuned for quality information to help keep your family safe, while The Lange Law Firm, PLLC strives to Make Food Safe!
By: Heather Van Tassell (contributing writer, non-lawyer)