Funded by the Kay Yow Cancer Fund
A growing body of scientific evidence suggests that up to half of all young women’s breast cancers are related to a recent pregnancy. Approximately 12,000-15,000 young mothers each year in the U.S. and 180,000 women worldwide will be diagnosed with breast cancer within 5 years of childbirth, demonstrating that young mother’s with breast cancer is a global problem. Our lab found that this population has a three-fold increase in metastasis and death, and we traced the increased death to the inflammatory effects of breast tissue “remodeling” following pregnancy –the time when breast tissue is removed to phase out of the job of lactation. Using rodent models of postpartum breast cancer, we found that ibuprofen treatment given for only 10 days after weaning blocks the development of postpartum breast cancers. Studies supported by the Kay Yow Cancer Fund permitted us to use our mouse models to determine whether ibuprofen can be used to prevent postpartum breast cancer, as well as let us investigate whether ibuprofen can be used to help treat young women already diagnosed with postpartum breast cancer. Our goal is to determine if a relatively low-cost intervention, such as ibuprofen or aspirin, can be readily incorporated into current treatment regimens to prevent the occurrence and/or progression of young women’s breast cancer. Results from this Kay Yow Cancer Fund grant confirm that the window of time following weaning is unique, characterized by tissue remodeling that is driven by the same protein that drugs like aspirin and ibuprofen inhibit. We anticipate that aspirin and ibuprofen, when combined with standard of care treatments for breast cancer, will reduce mortality in young women diagnosed with postpartum breast cancer. Further, our mouse studies identify why ibuprofen prevents progression of postpartum breast. We find that postpartum breast cancers are infiltrated with high levels of “bad” immune cells that block the ability of “good” immune cells to attach the cancer. We find that ibuprofen specifically blocks these “bad” immune cells and activates the “good” immune cells, permitting tumor destruction. In future studies, we will confirm that ibuprofen and drugs similar to ibuprofen activate the “good” arm of the immune system in postpartum women, as we see in mice, and we will conduct the first clinical trial designed to fight postpartum breast cancer.