Immunotherapy for inflammatory breast cancer: current evidences and future perspectives

Purpose of review Inflammatory breast cancer (IBC) is the most fatal type presentation of clinical breast cancer. The immune tumor microenvironment (TME) of IBC is characterized by signals of immune evasion but suggests actionable vulnerability to immune-checkpoint inhibitors (ICIs). In this review, we aimed to summarize the most important preclinical evidences of IBC immune-vulnerability and the first data from clinical trials evaluating ICIs in IBC. Recent findings IBC is characterized by a preexisting active immune TME suppressed by mechanisms of immune-escape, including inhibitory immune-checkpoints, whose expression is higher than in non-IBC. Clinical trials evaluating ICIs in patients with IBC are burdened by slow accrual and low enrollment. Summary Because of the limited data from clinical trials, no conclusions about the activity of ICIs in IBC can be drawn. Ongoing clinical trials are assessing many promising ICI-based combination approaches. An enhanced multicenter collaboration to evaluate ICIs in patients with this aggressive form of disease and to improve clinical outcomes is required.