Update of advanced cutaneous squamous cell carcinoma.

The incidence of cutaneous squamous cell carcinoma (cSCC) is rapidly increasing. A growing part of this patient group is formed by immunocompromised patients, for example organ-transplant recipients (OTR). Although over 90% of the cSCC show a relatively harmless clinical behaviour, there is also a chance of developing advanced cSCC and metastases. Locally advanced cSCC are defined as cSCC that have locally advanced progression and are no longer amenable to surgery or radiation therapy. Better understanding of the clinical behaviour of cSCC is essential to discriminate between low- and high-risk cSCC. Staging systems are important and have recently been improved. Genetic characterisation of SCC will likely become an important tool to help distinguish low and high-risk cSCC with an increased potential to metastasise in the near future. Available treatments for high-risk and advanced cSCC include surgery, radiotherapy, chemotherapy and targeted therapy with epidermal growth factor receptors inhibitors. Anti-PD-1 antibodies show promising results with response rates of up to 50% in both locally advanced and metastatic cSCC but, in its present form, is not suitable for OTR.