Breast Cancer Study of Preoperative Pembrolizumab + Radiation

With more than 1 million new cases diagnosed yearly worldwide, breast cancer is a global public health burden. Over the past decade, molecular subtyping of breast cancer has identified intrinsic subtypes that may be at enhanced risk for both local and distant recurrence. This study focuses on the immunogenicity of high-risk breast cancer subtypes that are likely to display a dense lymphocytic infiltration including including TNBC and HR+/HER2- tumors. Immune build up via immune co-stimulatory molecules permits the ensuing immune response to strengthen and destroy cancer systemically. Thus, the effect of the anti-tumor immune response initiated by the radiation to an intact tumor by combination with checkpoint blockade is increased. Pembrolizumab is an optimal immunotherapy agent to study, as this agent has recently been FDA approved for use in multiple tumor types. It is therefore ready to be tested for efficacy in other disease sites and in combination with other treatments.