Fusobacterium, which is commonly found in our mouths, could become the foundation of a future treatment for head and neck cancers. — Filepic
A common type of bacteria has been found to make certain cancers “melt”, scientists in the United Kingdom have discovered.
The researchers said that they were “brutally surprised” to find that Fusobacterium – a bacteria commonly found in the mouth – appears to have the ability to kill certain cancers.
People whose head and neck cancers were found to have this bacteria within their tumours have also been found to have “much better outcomes”, according to the new study.
The exact biological mechanisms behind the link are now being keenly studied by researchers at Guy’s and St Thomas’ NHS Foundation Trust, and King’s College London, after they made the initial finding.
Their original study, conducted in collaboration with an international team of researchers, used a number of different methods to study the link.
Modelling was used to help identify which bacteria may be of interest to further investigate.
They then studied the effect of the bacteria on cancerous cells in the laboratory, as well as performed an analysis on the data of 155 patients with head and neck cancer whose tumour information had been submitted to the Cancer Genome Atlas database.
The academics initially expected a completely different outcome as previous research has linked Fusobacterium to the progression of bowel cancer.
In the laboratory, quantities of the bacteria were put together with head and neck cancer cells in petri dishes, and left for a couple of days.
When the scientists returned to inspect the effect of the bacteria on the cancer, they found that there was a 70% to 99% reduction in the number of viable cancer cells in the petri dishes.
The analysis of the patient data also found that those with Fusobacterium bacteria within their cancer had better survival odds, compared with those who did not.
The presence of the bacteria was associated with a 65% reduction in risk of death, compared with patients whose cancers did not contain the bacteria.
New potential treatment
The researchers hope that the finding could help guide treatment for patients with head and neck cancer, which includes cancers of the mouth, throat, voice box, nose and sinuses.
Experts said that there have been few therapeutic advances in head and neck cancer in the last 20 years, so it is hoped that this finding could potentially lead to new treatments in the future.
“In essence, we found that when you find these bacteria within head and neck cancers, they have much better outcomes.
“The other thing that we found is that, in cell cultures, this bacterium is capable of killing cancer,” said senior study author Dr Miguel Reis Ferreira.
”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.”
The Guy’s and St Thomas’ consultant clinical oncologist and King’s College senior clinical lecturer added: “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.
“However, this finding should be balanced by their known role in making cancers, such as those in the bowel, get worse.”
A eureka moment
Dr Reis Ferreira said that before the lab work led by Dr Anjali Chander, the team expected for Fusobacterium to encourage the cancers to grow or make them more resistant to radiotherapy.
But they actually found that “at the end of a few days, it just destroys the cancer completely”.
“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.
“When we started finding things the other way around, we were brutally surprised.”
He added: ”You put it in the cancer at very low quantities and it just starts killing it very quickly.
”And then we got the validation cohort in collaboration with an Italian group from Milan via (researcher) Tiziana Rancati.”
Study lead author and King’s College senior clinical research fellow Dr Anjali added: “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.”
Dr Reis Ferreira added: “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.”
The study was published in the journal Cancer Communications. – PA Media/dpa
