Among some of the most remarkable discoveries made by researchers, a common form of bacteria residing in the mouth is capable of “melt” certain types of head and neck cancers. It has left scientists “brutally surprised,” as until now this very bacterium, Fusobacterium, had been linked to the advancement of bowel cancer in various studies.
A study carried out by researchers at Guy’s St Thomas’ and King’s College London, together with an international team of other researchers, has now revealed that patients whose head and neck cancers contain Fusobacterium do substantially better. The exact biological mechanisms by which this happens are now being intensively investigated.
The findings confirm that the researchers reduced the risk of death from cancers by 65 percent in those patients with Fusobacterium, said Dr. Miguel Reis Ferreira, a consultant in head and neck cancers at Guy’s and St. Thomas’ and senior clinical lecturer at King’s College London. “In essence, we found that when you find these bacteria within head and neck cancers, they have much better outcomes,” he said.
The research team used modeling to pinpoint bacteria of interest and test their link to cancer in the lab, then analyzed data from 155 patients with head and neck cancer. Researchers placed the bacteria in a Petri dish with cancer cells, and a few days later, the cancer cells had virtually vanished. The viable reduction of cancer cells ranged from 70 to 99 percent.
You put it in the cancer at very low quantities and it just starts killing it very quickly,” Dr. Reis Ferreira said, citing that based on its role already described in colorectal cancer, they thought Fusobacterium was going to encourage cancer growth or make it impervious to radiotherapy. However, they became more than surprised when they found out that the bacteria even destroyed the cancer cells.
Dr. Anjali Chander, a senior clinical research fellow at King’s College London and the lead author of the study, said the results are “remarkable and very surprising.” She added that there was a real “eureka moment” when overseas colleagues checked their results against further data.
The implications of this research could be deep and may guide new treatment strategies for head and neck cancers, which include cancers of the mouth, throat, voice box, nose, and sinuses. According to Dr. Reis Ferreira, the presence of Fusobacterium may help in the prediction of patient outcomes and tailoring of treatments.
Barbara Kasumu, executive director of Guy’s Cancer Charity, which part-funded the research, said she was “incredibly proud” it had supported this “ground-breaking research” into understanding and treating head and neck cancer.
The researchers, however, have tempered the discovery by pointing out how complex Fusobacterium’s involvement in cancer is. Dr Reis Ferreira said that any benefit of its presence had to be weighed against the known impact it has in exacerbating bowel cancer.
The findings were published in the journal Cancer Communications, in which it was reported that Fusobacterium is “toxic” for head and neck cancer, possibly leading to better outcomes in affected patients.
The discovery points toward new avenues of treatment in cases with cancer and further complicates the link between bacteria and cancer, a finding that should turn many previous beliefs around and give hope for more appropriate therapies in the future.