Gut Microbiome Plays A Role in Some Metastatic Breast Cancer

Recent research investigating the gut microbiome has revealed many new surprises about human health.  The latest study out of the University of Virginia intimates that an unhealthy belly might increase risk for the spread of breast cancer. Researchers say they found that altering a certain collection of microorganisms in the human gut could have a major impact on the body. 

Specifically, the researchers says they found this alteration results in hormone receptor-positive breast cancer becoming more aggressive and more vulnerable to spreading.  This is important, of course, because hormone receptor-positive breast cancer accounts for roughly 65 percent of all breast cancer cases.  More importantly, this form of cancer is known to spread rapidly from the breast to the lymph nodes and even the lungs.  

This quickly metastatic progression is among the biggest challenges doctors and clinicians face in successfully treating the disease. Oddly enough, the cancer does respond quite effectively to hormone therapy; the problem lies within the fact that it is hard to determine what factors will promote an earlier metastatic spread.

Study author Melanie Rutkowski of the UVA Department of Microbiology, Immunology, and Cancer Biology, explains “When we disrupted the microbiome’s equilibrium in mice by chronically treating them with antibiotics, it resulted in inflammation systemically and within the mammary tissue.” 

She notes that tumor cells in growing in this “inflamed environment” are better at disseminating from this tissue into the blood and then onto the lungs.  Unfortunately, the lungs are a prolific site for hormone receptor-positive breast cancer cells to settle and metastasize.

The study verified, then, that there is a causal relationship between the gut microbiome dysbiosis and metastatic cancer. The researchers managed to replicate the experiment with fecal microbiota transplantation that disrupts animal microbiome samples.  While the results were smaller, they do suggest the gut microbiome does, in fact, play a role in tissue inflammation regulation and the spread of metastatic cancer. 

At the end of the day, Rutkowski advises “These findings suggest that having an unhealthy microbiome, and the changes that occur within the tissue that are related to an unhealthy microbiome, may be early predictors of invasive or metastatic breast cancer. 

She goes on to say, this discovery could be applicable to many types of cancers, which actually could make it a “general diagnosis tool for predicting metastatic disease.”  Rutkowski intimates that the better we can understand how the gut contributes to more invasive cancers, the more adept we may be at developing specific therapies designed to target them.