Immune checkpoint inhibitors for advanced or metastatic basal cell carcinoma: how much evidence do we need?

Basal cell carcinoma (BCC) is one of the most frequent and most curable tumors at its early stages. BCC rarely metastasizes and its treatment in this setting is still challenging. Hedgehog inhibitors showed an activity in advanced or metastatic disease. However, there is an unmet need for new agents. Immune checkpoint inhibitors have been assessed in melanoma and other cutaneous tumors, and very recently an anti-PD1 was approved for advanced BCC. In this paper, available data are reviewed on experimental and preclinical studies evaluating immunotherapy in BCC, as well as on the clinical evidence supporting the efficacy and safety of immune checkpoint inhibitors for advanced or metastatic BCC based on case reports, case series and clinical trials.