New Irish research has found a possible relationship between the presence of a specific type of bacteria found in tumours and the spread of bowel (colorectal) cancer.

Over 2,800 people are diagnosed with bowel cancer every year in Ireland and the disease accounts for 10% of all new cancer diagnoses worldwide.

It is hoped that these findings will help clinicians to identify patients who are at risk of poorer outcomes, leading to better treatment options for some.

Using genomic sequencing, researchers are now able to detect traces of an infection with bacteria or other microbes in patients’ tumours - something that would previously have been undetectable.

Research led by the RCSI University of Medicine and Health Sciences 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 researchers 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 the bacteria, Fusobacterium nucleatum, and the spread of bowel cancer, which could result in poorer outcomes for certain patients.

“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.

“We hope these finding  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,” explained the study’s lead researcher, Prof Jochen Prehn, of the RCSI University of Medicine and Health Sciences.

Collaborating with Queen’s University Belfast, the researchers analysed samples from patients from Northern Ireland and from over 600 patients from the Cancer Genome Atlas – 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.

The study was supported by the RCSI and the Irish Centre for High-End Computing (ICHEC) and funded by the Health Research Board, Science Foundation Ireland and the Northern Ireland Department for the Economy (NI DfE).

Details are published in the journal, Gut, and can be viewed here.