Invasive Keratinocyte Carcinomas

Nonmelanoma skin cancers, now called keratinocyte carcinomas, refer to all types of cutaneous malignancies that are not melanoma and comprise the two most common types: basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC). These two cutaneous malignancies rarely metastasize, but they can result in considerable morbidity, primarily through local destruction. Other nonmelanoma skin cancers, like Merkel cell carcinoma, sarcoma, and adenocarcinoma, are rare. Although surgical excision with subsequent histological examination of the margins is the first-line treatment for invasive cancers, targeted therapies, such as inhibitors of hedgehog pathways for BCC, and immune checkpoint inhibitors for cSCC, are successfully used for metastatic, locally advanced, or inoperable cancers.