Profiling bacterial populations in breast cancer tissue

Profiling bacterial populations in breast cancer tissue

Project Overview

Breast cancer is the most common female cancer with an incidence of 13,000 Australian women diagnosed each year and a survival rate approaching 85%.  

Whilst many risk factors have been associated with family history, hormone and alcohol intake, three-quarters of women with breast cancer will not display any of these risk factors, which suggests that our understanding of the cause of breast cancer is incomplete.  

This research project investigated and compared the bacterial communities in healthy and malignant breast cancer tissue using an entirely novel methodology for the isolation, enrichment and detection of low copy number bacteria within human tissue.

Study Completed

August 2018

Total Samples Analysed


Study Location

The Wesley Hospital

Project Aim

The overall aim of this research was to determine if there is evidence that breast cancer tissue is associated with a microbiome (bacterial community) that differs to that found in normal breast tissue. 

The premise underlying this aim is that if alterations in the tissue microbiome contribute to breast cancer formation or behaviour then this would be observable via changes in the bacterial communities as measured by bacterial genome mapping.

Project Impact

Our study found that breast cancer tissue has a greatly reduced bacterial burden compared to the surrounding normal tissue. 

Previous studies have shown that not all bacteria are bad.  Indeed, we actually need good bacteria to maintain good health.  Because our study shows that breast cancer tissue has a greatly reduced bacterial burden this may suggest that the loss of “good bacteria” from breast tissue may be associated with breast cancer development. 

Significantly, we found that cancer tissue adjacent to the normal tissue had almost undetectable levels of bacteria. 

This suggests that the normal healthy breast has a small healthy bacterial community whereas breast cancer has little if any.  This is highly suggestive of a role of bacterial loss in breast cancer formation.  In other words, it may be that we need bacteria to maintain breast health and that loss of these “healthy” bacteria may contribute to the formation of breast cancer.  


A/Prof Ian C Bennett
Breast and Endocrine Surgeon
Lead Researcher

The findings from this study will be pursued in a future study to see whether targeting health breast bacteria could be used to prevent or retard breast cancer formation.

A/Prof Ian C Bennett, Lead Researcher

Stories about this project

Wesley Medical Research

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