Breast cancer is the most common cancer among Canadian women and the second leading cause of cancer-related death. Estrogen is a known cause of the most common type of breast cancer (HR-positive). Bacteria in the gut can control estrogen levels and animal models suggest this may contribute to breast cancer. However, studies in humans are very limited. To understand whether estrogen-related gut bacteria play a role in breast cancer development, we will conduct a study of 70 women newly diagnosed with HR-positive breast cancer and 70 women without cancer (controls). Participants will be asked to complete questionnaires on dietary intake and health factors and provide a stool sample before and after they receive hormone therapy or over the same time period for controls. The type and amount of bacteria will be measured using state-of-the-art technologies that measure all genes in a given sample and small molecules that participate in metabolism (metabolites). These results will provide new knowledge on how the microbiome may contribute to development of breast cancer, and new approaches to reduce the burden of breast cancer on women and their families.
We are looking at how the gut microbiome impacts the development of breast cancer. Health surveys, stool and blood samples will be required from participants. If interested, go to https://redcap.link/breast.health to see if you are eligible.