The presence of a particular bacterium in oesophageal tumours could be linked to lower survival, according to a new Japanese study.
The research, from scientists at Kumamoto University in Japan, found that people whose tumours tested positive for DNA from the common bacterium Fusobacterium nucleatum were more likely to do worse than those whose tumours tested negative.
The findings don’t prove the bacterium causes oesophageal cancer or poorer survival, but the researchers believe that testing for the DNA could be used to help predict patient outlook.
But they stressed that larger studies would be needed to confirm the link.
“If they [the results] are replicated in a large, international, multi-institutional study, such testing could provide physicians with important information to consider while deciding how best to manage the care of a patient with oesophageal cancer,” said Professor Hideo Baba, lead author of the study published in the journal Clinical Cancer Research.
The team studied 325 oesophageal cancer samples from patients in Japan and looked for the presence of F. nucleatum DNA.
This species of bacteria is part of the normal collection of microbes found in the body – called the microbiome. But it has also previously been linked with poor outlook in bowel cancer.
The researchers found more of the bacterial DNA in tumour samples than the healthy oesophageal samples they were compared with.
And after taking into account various factors associated with survival – such as age, tobacco use and tumour stage – patients with tumours that were positive for the bacterial DNA were more likely to have died as a result of oesophageal cancer.
Dr Lesley Anderson, a Cancer Research UK expert in oesophageal cancer, said that if a role can be confirmed in further studies, the work “could lead to new treatments and better outcomes for some patients.”
“This is the first study to suggest that this particular bacterium may be found in around a quarter of oesophageal cancer samples,” added Anderson.
“As the study just included samples from Japanese patients, it’s not yet clear how common this link might be. But patients whose samples did carry the bacteria appeared to have worse outcomes.
“And if the bacterium is found to be involved in the development of some oesophageal cancers, there may be potential to prevent some cancers in high risk patients.”
Yamamura, K. et al. 2016. Human microbiome fusobacterium nucleatum in esophageal cancer tissue is associated with prognosis. Clinical Cancer Research. DOI: 10.1158/1078-0432