Bowel cancer potentially linked to specific bacteria – RCSI Study

Bowel cancer may be linked to the presence of a specific type of bacteria in a patient’s gut, new research from the RCSI University of Medicine and Health Sciences has found.

Published in the leading gastroenterology journal Gut, findings of the research may help clinicians to identify patients at risk of poorer outcomes, and make decisions on treatment options for patients with bowel cancer whose tumours are infected with the bacterium Fusobacterium nucleatum.

Using genomic sequencing, researchers can now detect traces of an infection with bacteria or other microbes in patients’ tumours that previously would have been undetectable. The RCSI-led research set out to understand which tumours are infected with bacteria, and what the role of a bacterial infection means in terms of how the disease progresses. The research found that a collection of bacteria that normally lives in the oral cavity infects bowel tumours, changes how tumour cells behave, and may trigger the spread of the tumour to other organs.

The study suggests that there is a direct relationship between the presence of a bacteria called Fusobacterium nucleatum and the spread of bowel cancer resulting in poorer outcomes for a subset of patients.

Lead researcher, Jochen Prehn, Professor of Physiology and Director of the Centre for Systems Medicine at RCSI, said that an effective tool to help oncologists to personalise colorectal cancer treatment is urgently needed. “This study demonstrates the role that bacteria play in the spread of bowel cancer in patients,” he said. “We hope these findings will enhance diagnostics to improve the efficacy of current treatment and help further advance the use of new therapeutics for patients infected with this bacterium.”

According to the Irish Cancer Society, almost 3,000 people are diagnosed with bowel cancer in Ireland each year and worldwide, bowel cancer accounts for approximately 10% of new cancer cases. In this collaborative study with Queen’s University Belfast, samples from patients from Northern Ireland and from over 600 patients from the Cancer Genome Atlas were analysed.

The Cancer Genome Atlas is an international programme that analyses the genetic mutations responsible for cancer types to help researchers and clinicians to better understand the disease and how to treat it.