Towards less mutilating treatments in patients with advanced non-melanoma skin cancers by earlier use of immune checkpoint inhibitors.

Merkel cell carcinoma (MCC), advanced cutaneous squamous cell carcinoma (cSCC), and advanced basal cell carcinoma (BCC) are rare, and the often frail patients may require potentially mutilating local treatments. Immune checkpoint inhibitors (ICIs) are effective in melanoma and are moving towards the neoadjuvant setting. This systematic review explores data supporting the transition of ICIs from the metastatic to the (neo)adjuvant setting non-melanoma skin cancer (NMSC) and describes how knowledge from melanoma can be utilized. ICI response rates in advanced NMSC and melanoma are comparable. Five early phase studies show effectivity of neoadjuvant ICIs in melanoma and adjuvant treatment is standard-of-care. Eight adjuvant and 12 neoadjuvant ICI studies are ongoing for NMSC. Encouragingly, data from two small neoadjuvant ICI studies in NMSC, demonstrated complete responses in approximately half of patients. In conclusion, neoadjuvant ICI treatment has potential to avert mutilating treatments in NMSC. Progress can be accelerated by learning from melanoma.