Bacteria could become new biomarker for testing patients’ reaction to cancer treatments which would give microbiologists and clinical laboratories a new tool for aiding diagnosis and in the selection of appropriate therapies
In a surprising study conducted at King’s College London and Guy’s and St Thomas’ NHS Foundation Trust, British scientists have discovered that a common bacteria found in the mouth may be able to “melt” certain cancers. The bacteria could also be used as a clinical laboratory biomarker to determine how patients may react to specific cancer treatments.
The researchers found that the presence of Fusobacterium can help neutralize head and neck cancers and provide better outcomes in patients with those diseases, according to a Kings College London news release.
Fusobacterium is a genus of anaerobic gram-negative bacteria that are prevalent colonizers of the mouth microbiome. It can be associated with mouth abscesses, periodontal disease, skin ulcers, and Lemierre’s syndrome. The most common species of the genus, Fusobacterium nucleatum, is a marker for the early prediction, diagnosis, and prognosis of colorectal cancer.
“In essence, we found that when you find these bacteria within head and neck cancers, [patients] have much better outcomes,” said Miguel Reis Ferreira, MD, PhD, clinical oncologist at Guy’s and St Thomas’, adjunct senior clinical lecturer at King’s College London and senior author of the study, in the news release. “The other thing that we found is that in cell cultures this bacterium is capable of killing cancer.”
The researchers published their findings in the journal Cancer Communications titled, “Fusobacterium is Toxic for Head and Neck Squamous Cell Carcinoma, and its Presence May Determine a Better Prognosis.”
“This research reveals that these bacteria play a more complex role than previously known in their relationship with cancer—that they essentially melt head and neck cancer cells,” said Miguel Reis Ferreira, MD, PhD (above), clinical oncologist at Guy’s and St Thomas’, adjunct senior clinical lecturer at King’s College London and senior author of the study, in a news release. “However, this finding should be balanced by their known role in making cancers such as those in the bowel get worse.” Should these findings prove sound, clinical laboratories may soon have a new biomarker for testing patients’ reaction to cancer treatments. (Photo copyright: King’s College London.)
Researchers Surprised by Their Findings
The researchers began their research by using computer modeling to identify the types of bacteria to further scrutinize. They then studied the effect of those bacteria on cancer cells by analyzing data on 155 head and neck cancer patients whose tumor information had been submitted to the Cancer Genome Atlas. Head and neck cancers include cancers of the mouth, throat, voice box, nose, and sinuses.
The scientists placed Fusobacterium in petri dishes and kept the bacteria there for a few days. They observed the effect of that bacteria on head and neck cancers and discovered there was a 70% to 90% reduction in the number of viable cancer cells after being infused with the Fusobacterium.
Due to the known correlation between Fusobacterium and colorectal cancer, the team was astonished to find the cancer cells present in head and neck cancers had almost been eradicated.
In the news release, Ferreira said the researchers initially expected the Fusobacterium to boost the growth of the cancers and render those cancers more resistant to treatments like radiotherapy. However, they found the opposite to be true.
“The research in colorectal cancer indicates that these bacteria are bad, and that was kind of ingrained into our minds, and we were expecting to find the same thing,” said Ferreira in a Press Association (PA) interview, The Independent reported. “When we started finding things the other way around, we were brutally surprised.”
Predicting Better Outcomes, Lower Risk of Death
“You put it in the cancer at very low quantities and it just starts killing it very quickly,” Ferreira said in the King’s College London news release. “What we’re finding is that this little bug is causing a better outcome based on something that it’s doing inside the cancer. So we are looking for that mechanism at present, and it should be the theme for a new paper in the very short-term future.”
In addition, the scientists discovered that patients with Fusobacterium within their cancer showed improved survival rates when compared to those without the bacteria. The presence of the bacteria correlated with a 65% reduction in death risk.
“What it could mean is that we can use these bacteria to better predict which patients are more likely to have good or worse outcomes, and based on that, we could change their treatment to make it kinder in the patients that have better outcomes or make it more intense in patients that are more likely to have their cancers come back,” said Ferreira in the PA interview.
“Our findings are remarkable and very surprising. We had a eureka moment when we found that our international colleagues also found data that validated the discovery,” said Anjali Chander, PhD student, senior clinical research fellow, Comprehensive Cancer Center, King’s College London, and lead author of the study in the news release.
More to Learn about Bacteria as Biomarkers
According to the National Cancer Institute (NCI), more than 71,000 people will be diagnosed with one of the major types of head and neck cancer this year in the US and more than 16,000 patients will die from these diseases.
The Global Cancer Observatory (GLOBOCAN) estimates there are about 900,000 new cases of head and neck cancers diagnosed annually worldwide with approximately 450,000 deaths attributed to those cancers every year. GLOBOCAN also claims head and neck cancers are the seventh most common cancer globally.
More research and studies are needed to confirm the virtue of this latest venture into the human microbiome. However, the preliminary results of this study appear promising.
The study of human microbiota continues to bring unexpected surprises, as scientists gain more insights and identify specific strains of bacteria that may have a positive or negative influence on an individual’s health. These discoveries may give microbiologists and clinical laboratories intriguing new biomarkers that could be incorporated into medical tests that aid diagnosis and the selection of appropriate therapies.
—JP Schlingman
Related Information:
Type of Mouth Bacteria ‘Melts’ Some Cancers, Study Finds
Bacteria ‘Melts’ Head and Neck Cancer in Revolutionary Discovery
Bacteria ‘Melts’ Head and Neck Cancer in Revolutionary Discovery
Common Mouth Bacteria Found to ‘Melt’ Certain Cancers in ‘Surprising’ Discovery
Fusobacterium Nucleatum, a Key Pathogenic Factor and Microbial Biomarker for Colorectal Cancer