The Role of Immunotherapy in Breast Cancer and Mechanisms of Immune Escape: What Surgeons Need to Know.

Immunotherapy has revolutionized the treatment of cancer, including the treatment of breast cancer. As immunotherapy becomes more widely used in this context, we must also understand the mechanisms of immune evasion and treatment resistance. In this review, we provide a historical context and overview of breast cancer immunology, describe the current indications for immunotherapy, and define mechanisms of immune escape and the tumor microenvironment (TME) across breast cancer subtypes. We also describe future therapeutic directions. It is critical that surgeons are aware of the changing systemic therapy landscape. As these new therapies are integrated into practice, we must work with our multidisciplinary teams to determine optimal patient selection, to determine optimal treatment sequencing, and to better understand the surgical risk factors associated with new therapies.