Researchers at the NIHR Biomedical Research Centre: Leeds have identified which cancer tumours carry their own microbiome, a discovery that could pave the way for more targeted, personalised cancer treatments.
Our goal
To resolve conflicting evidence on whether tumours contain their own microbiome (bacteria, fungi and viruses) and to work out which cancers this applies to so that microbiome-based tests or treatments can be targeted where they will best help patients.
Our approach
NIHR Biomedical Research Centre: Leeds’ Pathology theme, working with colleagues at the Harvard Medical School-affiliated Dana-Farber Cancer Institute, developed a new computational method called PathSeqT2T to detect microbial DNA within tumour samples while stripping out human DNA and contamination.
Researchers applied this method to over 16,000 tumour DNA samples from the 100,000 Genomes Project, spanning a wide range of cancer types. After removing contamination, we compared microbial signatures across cancer types to establish which, if any, harbour their own microbiome and how this relates to a tumour’s genetic profile.
Real-world impact
Leeds researchers identified which cancer tumours have their own microbiome, paving the way for more effective, more personalised treatments. This helps resolve a long-standing scientific debate over whether microbes live within tumours or whether previous findings were simply contamination.
Cancers of the mouth, throat, stomach, intestines and related organs were found to have their own microbiome, including bacteria, fungi, viruses, archaea and, in some cases, the parasite Trichomonas, which can spread through sexual contact.
What was present depended on tumour type: tumours with more genetic mutations tended to carry more microbes. In bowel cancer specifically, the microbes present varied depending on where in the bowel the tumour developed and the patient’s age at diagnosis.
This matters for patients because it pinpoints where microbes may influence cancer development, diagnosis or treatment, and where they don’t, meaning microbiome-based therapies or tests can be targeted at specific cancers rather than applied broadly.
This work supports NIHR’s goal of reducing lives lost to the biggest killers and reflects Leeds Teaching Hospitals’ wider drive to develop AI-enabled digital pathology tools for earlier, more precise cancer diagnosis.