Unhealthy Gut Helps Breast Cancer Spread, Research Reveals
An unhealthy gut triggers changes in normal breast tissue that helps breast cancer spread to other parts of the body, new research from UVA Cancer Center reveals.
The gut microbiome – the collection of microbes that naturally live inside us – can be disrupted by poor diet, long-term antibiotic use, obesity or other factors. When this happens, the ailing microbiome reprograms important immune cells in healthy breast tissue, called mast cells, to facilitate cancer’s spread, UVA Health’s new discovery shows.
The finding could help scientists develop ways to keep breast cancer from metastasizing (spreading to other parts of the body). When it does, it is often deadly: Only 29% of women with metastatic breast cancer survive five years; for men with metastatic breast cancer, that figure is just 22%.
The discovery could also let doctors predict which patients are at greatest risk of cancer recurrence after treatment, the UVA scientists say.
“We show gut commensal dysbiosis, an unhealthy and inflammatory gut microbiome, systemically changes the mammary tissues of mice that do not have cancer. The tissue changes enhance infiltration of mast cells that, in the presence of a tumor, facilitate breast tumor metastasis,” said researcher Melanie R. Rutkowski, PhD, of UVA Cancer Center and the University of Virginia School of Medicine. “Mast cells recruited into the tissue environment during dysbiosis restructure the tissue architecture in such a way that tumor cells metastasize to other organs.”
The Microbiome and Breast Cancer
Rutkowski has been a pioneer in unveiling the surprising relationship between gut health and breast cancer. Her latest work reveals complex interactions between our gut microbes and mast cells in the breast. Mast cells are blood cells which help regulate the body’s immune response to disease and allergens. Rutkowski’s new work suggests that the gut microbiome can systemically influence mast cell behavior and function in the presence of tumors.
Rutkowski and her team found that an unhealthy microbiome caused the mast cells to accumulate in the breast. These changes continued after tumor formation in a mouse model of hormone receptor-positive breast cancer, making the breast tissue a prime launching ground for the cancer’s incursions into other parts of the body.
