Breast cancer linked to bacterial imbalances: study

Washington: Scientists have discovered for the first time that bacterial composition of tissues in women with breast cancer differ from those of healthy people, a finding which could offer a new perspective in the battle against the deadly disease.

Researchers found that breast tissues of healthy women contain more of a bacterial species Methylobacterium. Bacteria that live in the body, known as the microbiome, influence many diseases. Most research has been done on the "gut" microbiome, or bacteria in the digestive tract.

It has been long suspected that a "microbiome" exists within breast tissue and plays a role in breast cancer but it has not yet been characterised. Research from Cleveland Clinic in the US took the first step towards understanding the composition of the bacteria in breast cancer by uncovering distinct microbial differences in healthy and cancerous breast tissue.

"To my knowledge, this is the first study to examine both breast tissue and distant sites of the body for bacterial differences in breast cancer," said Charis Eng, chair of Cleveland Clinics Genomic Medicine Institute.

"Our hope is to find a biomarker that would help us diagnose breast cancer quickly and easily," said Eng. "In our wildest dreams, we hope we can use microbiomics right before breast cancer forms and then prevent cancer with probiotics or antibiotics," he said.

The study examined the tissues of 78 patients who underwent mastectomy for invasive carcinoma or elective cosmetic breast surgery. In addition, they examined oral rinse and urine to determine the bacterial composition of these distant sites in the body.

In addition to the Methylobacterium finding, the team discovered that cancer patients urine samples had increased levels of gram-positive bacteria, including Staphylococcus and Actinomyces. Further studies are needed to determine the role these organisms may play in breast cancer.

"If we can target specific pro-cancer bacteria, we may be able to make the environment less hospitable to cancer and enhance existing treatments, said Stephen Grobymer, head of Surgical Oncology at Cleveland Clinic. "Larger studies are needed but this work is a solid first step in better understanding the significant role of bacterial imbalances in breast cancer," said Grobmyer, also the director of Breast Services at Cleveland Clinic.

The study, published in the journal Oncotarget, provides proof-of-principle evidence to support further research into the creation and utilisation of loaded nanoparticles targeting these pro-cancer bacteria.