The first study of the microbiome––the community of microorganisms––in human breast ductal fluid has shown differences between the bacteria found in women who have experienced breast cancer and the bacteria present in those who have not. The study results open the door to the investigation of the potential role of microbes in breast cancer development, according to the investigators.
Published in the online journal Scientific Reports, the study was conducted by a multi-institutional team from the Dr. Susan Love Research Foundation in Encino, California; the John Wayne Cancer Institute at Providence Saint John’s Health Center in Santa Monica, California; and the National Aeronautics and Space Administration (NASA) Jet Propulsion Laboratory at the California Institute of Technology in Pasadena, California.
Before the new study was conducted, researchers had documented the existence of bacteria in breast tissue. However, this collaboration marks the first exploration of a link between the breast ductal-fluid microbiome and breast cancer.
“We don’t yet know nearly enough about healthy and cancerous breasts––neither the microbial landscape nor the anatomy of the breast duct system,” lead investigator Susan Love, MD, MBA, said. “Yet, all breast cancer begins in the ducts, so clearly exploration is critical to discovering what causes breast cancer and how we can eradicate the disease.”
The researchers found that the microbiome in breast ductal fluid differed significantly between two groups, 23 healthy women and 25 women who had a history of breast cancer. Fluid was obtained through suction on the nipple and was analyzed via next-generation genomic sequencing.
The research findings set the stage for further study of the role microbes may play in causing or preventing breast cancer. Recent research has suggested that microbes contribute to 16% or more of malignancies worldwide.
“We have known for decades that our immune cells and the cells that line our organs’ surfaces can react to microbial components,” said Delphine Lee, MD, PhD, of the John Wayne Cancer Institute. “These responses can trigger inflammation and immune responses, suggesting that this interaction might help the immune system monitor breast tissue for cancer, or that certain microbes could contribute to increased inflammation that leads to cancer development. There is still so much to explore.”
Drawing on its expertise in genomic sequencing, a team at the NASA Jet Propulsion Laboratory employed a sophisticated data-analysis technique to identify the bacteria existing in the breast ductal fluid. Used primarily to characterize the microbial ecology related to outbound spacecraft in an effort to protect other worlds, this analytical methodology is proving useful in disciplines other than astrobiology.