Non-melanoma skin cancer.

Non-melanoma skin cancer (NMSC) comprises basal cell carcinoma (BCC) and squamous cell carcinoma, together with a host of rare tumours. NMSC is the commonest malignancy among Caucasians and its incidence continues to rise annually. Exposure to UV radiation initiates approximately 90% of NMSC, causing malignant transformation of keratinocytes and suppression of the inflammatory response. Risk factors include sun exposure and immunosuppression. There are several subtypes of BCC, although histological overlap is common. Surgery has traditionally been regarded as the 'gold-standard' treatment, offering excellent cure rates and cosmetic results. Other treatment modalities include physical destruction (radiotherapy, curettage and cautery, and cryotherapy), chemical destruction (photodynamic therapy and topical 5-flurouracil) and immunomodulatory therapy (topical imiquimod). The recent development of novel hedgehog pathway inhibitors for high-risk BCC (including oral vismodegib and sonidegib) may represent a paradigm shift towards medical management of NMSC.