Managing side effects of immune checkpoint inhibitors in breast cancer

Immune-checkpoint inhibitors (ICIs) represent a major development in cancer therapy. The indications for these agents continue to expand across malignancies and disease settings. For years breast cancer (BC) has been considered immunologically quiescent compared with other tumor types. However, recent findings highlighted the immunogenicity of some BCs and paved the way for clinical trials of immunotherapy in BC that led to recent landmark approvals. As a drawback, the safety profile of ICIs is shaped by a specific spectrum of immune-related adverse events (irAEs) that can vary according to ICI class and tumor histology. This review will discuss the epidemiology of these adverse events, their kinetics, risk factors and the most important aspects in their management. A particular focus will be put on BC as the current landscape of immunotherapy for this disease is rapidly increasing the number of people treated with ICIs, thus susceptible to irAEs.