Squamous Cell Carcinoma and its Precursors
Squamous cell carcinoma (SCC) is the second commonest skin cancer and arises from epidermal keratinocytes or its appendages. The incidence of SCC has increased over the last five decades and is predicted to rise significantly by 2030. SCC is predominantly a disease of white populations and is especially prevalent in this group in areas of high ambient sun exposure. Predisposing factors include male sex, immune suppression (particularly those who are organ transplant recipients), sun exposure and advanced age. There is an excess risk of SCC associated with all β human papillomavirus types. Precursor lesions such as actinic keratosis or Bowen disease may often be present and patients are more susceptible to developing other UV radiation‐induced skin cancers. SCC has a low rate of metastasis but this increases with SCCs displaying high‐risk features. All SCCs should undergo full clinicopathological correlation and high‐risk SCCs should be managed within a multidisciplinary setting with adequate tumour clearance as the main outcome.
Keywords squamous cell carcinoma, SCC, actinic keratosis, cutaneous horn, arsenical keratosis, disseminated superficial actinic keratosis, Bowen disease, keratoacanthoma, immunosuppression, human papillomavirus, HPV, high‐risk features