New evidence that a common gut bug is involved in bowel cancer has been uncovered by researchers at the Royal College of Surgeons in Ireland (RCSI)

Researchers from the Department of Physiology and Medical Physics in RCSI found a significantly increased presence of a common microbe Fusobacterium nucleatum (Fn) in tissue and stool samples of patients with colorectal cancers and colorectal benign tumours.

Additionally, Fn infection levels were related to benign tumours progressing from early to advanced stages and in the transition from a benign tumour to cancer.

Leader of the research project, Dr David Hughes, said the research found that cancer patients with low bacterial levels had significantly longer survival times than patients with moderate and high levels of the bacterium.

"Also, for patients with a benign tumour, we found that the presence of Fn may be a risk factor for disease progression from tumour to cancer."

Dr Hughes said this was  a significant finding as it highlighted the potential of Fn detection as a possible indicator of colorectal cancers."

The research indicates that screening for Fn levels may be used as a new bowel cancer detection method. 

Targeted efforts to combat Fn infection could in future be considered for colorectal cancers patients with high levels of the bacterium, in order to improve survival prospects, the researchers believe.

Dr Hughes said: "Potentially, any impact of Fn infection on benign tumour development and progression to more serious stages will be considerable, because 95% of all bowel cancers arise from benign tumours, but only a small number of them become cancerous."

"Currently, there are no reliable predictive markers of whether a benign tumour will advance to cancer."

The study, funded by the Health Research Board, is published in The European Journal of Clinical Microbiology & Infectious Diseases.

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