Tamoxifen is an often-used drug for treatment and, more recently, prevention of breast cancer.
While tamoxifen has been well-studied as a chemotherapeutic drug, there is still much to be learned about how it works as a preventative agent and how to optimize its effectiveness, Seewaldt said. While tamoxifen has shown promise in preventing breast cancer, we don't understand exactly how it works or how best to use it. In studies with human breast cells in the laboratory, Seewaldt observed that when normal breast cells initially have lost a gene called p53, they are extremely sensitive to tamoxifen, but fairly quickly the remaining cells develop resistance to the drug. This preliminary finding correlates well to the clinical observation that p53 mutations are associated with failure of tamoxifen treatment. Seewaldt now wants to examine the details of the link between the drug and p53.