Treatment of unresectable cutaneous squamous cell carcinoma with pembrolizumab

Currently, there are few effective therapies for locally advanced and metastatic cutaneous squamous cell carcinoma (cSCC); however, there is recent evidence supporting the use of immunological therapies in cSCC given the typically high mutation burden and association with immunosuppressed states. This report describes a 56-year-old man presenting with synchronous, invasive cSCC on the right temple and right dorsum of the hand deemed unfavourable for surgical resection. The patient was treated with nine infusions of programmed cell death protein 1 (PD-1) inhibitor therapy, pembrolizumab, with clinical and radiographical resolution of his lesions. This case illustrates the potential use of anti-PD-1 antibody as a first-line treatment in the setting of advanced, unresectable cSCC.