Immunological Landscape of HER-2 Positive Breast Cancer

SIMPLE SUMMARY: The aim of this work is to elucidate the role of immune response in HER2+ breast cancer. By describing the principal components of the tumour microenvironment and its interaction with the known and novel anti-HER2 targeted therapies, this review summarizes the ways immune modulators could be implemented in clinical practice. ABSTRACT: Understanding the biological aspects of immune response in HER2+ breast cancer is crucial to implementing new treatment strategies in these patients. It is well known that anti-HER2 therapy has improved survival in this population, yet a substantial percentage may relapse, creating a need within the scientific community to uncover resistance mechanisms and determine how to overcome them. This systematic review indicates the immunological mechanisms through which trastuzumab and other agents target cancer cells, also outlining the main trials studying immune checkpoint blockade. Finally, we report on anti-HER2 vaccines and include a figure exemplifying their mechanisms of action.