Immune Checkpoint Inhibitors in the Emergency Department

Immune-checkpoint inhibitors (ICIs) have transformed the landscape for cancer treatment by enhancing the endogenous immune system’s ability to eliminate cancer cells. Tumor cells evade the body’s immune response by blocking T cell activation; ICIs function by blocking this inhibition, thereby boosting the immune system’s ability to kill tumor cells. Despite producing astonishing improvements in prognosis and remission-free time frames for cancer patients, ICIs carry risks for well documented treatment-related complications and immune-related adverse events (irAEs) that can be life-threatening. IrAEs can occur in almost any organ system, and they usually occur early in treatment, typically within the first three months. Some common complications involve the cutaneous, gastrointestinal tract, pulmonary, and endocrine organ systems. Guidelines outlining the general treatment algorithms for irAEs have been published by the Society for Immunotherapy of Cancer (SITC) and the National Comprehensive Cancer Network (NCCN). When patients present to the Emergency Department with symptoms consistent with irAEs, a rigorous and thorough infectious work-up is required, and treatment usually begins. This includes immunosuppression with corticosteroids, symptomatic treatment, and/or discontinuation of the ICI depending on the grade and severity of presentation. Early recognition and management of irAEs among ED providers, in conjunction with treating oncologists, are imperative to improve patient outcomes in the Emergency Department.