Later stages of invasion are characterized by the formation of nests of atypical tumor cells in the dermis, often with a corresponding inflammatory infiltrate. Degree of differentiation
Prevention
Appropriate sun-protective clothing, use of broad-spectrum (UVA/UVB) sunscreen with at least SPF 50, and avoidance of intense sun exposure may prevent skin cancer. A 2016 review of sunscreen for preventing squamous cell skin cancer found insufficient evidence to demonstrate whether it was effective. Management
Most squamous cell carcinomas are removed with surgery. A few selected cases are treated with topical medication. Surgical excision with a free margin of healthy tissue is a frequent treatment modality. Radiotherapy, given as external beam radiotherapy or as brachytherapy (internal radiotherapy), can also be used to treat squamous cell carcinomas. There is little evidence comparing the effectiveness of different treatments for non-metastatic SCC of the skin.Mohs surgery is frequently utilized; considered the treatment of choice for squamous cell carcinoma of the skin, physicians have also utilized the method for the treatment of squamous cell carcinoma of the mouth, throat, and neck. An equivalent method of the CCPDMA standards can be utilized by a pathologist in the absence of a Mohs-trained physician. Radiation therapy is often used afterward in high risk cancer or patient types. Radiation or radiotherapy can also be a standalone option in treating SCCs. As a non invasive option brachytherapy serves a painless possibility to treat in particular but not only difficult to operate areas like the earlobes or genitals.
Erythroplasia of Queyrat may also occur on the anal mucosa or the oral mucosa. Some sources state that this condition is synonymous with Bowens disease, however generally speaking Bowens disease refers to carcinoma in situ of any location on the skin such as the lower leg. Genetically, SCC tumors harbor high frequencies of NOTCH and p53 mutations as well as less frequent alterations in histone acetyltransferase EP300, subunit of the SWI/SNF chromatin remodeling complex PBRM1, DNA-repair deubiquitinase USP28, and NF-κB signaling regulator CHUK. Immunosuppression
People who have received solid organ transplants are at a significantly increased risk of developing squamous cell carcinoma due to the use of chronic immunosuppressive medication. While the risk of developing all skin cancers increases with these medications, this effect is particularly severe for SCC, with hazard ratios as high as 250 being reported, versus 40 for basal cell carcinoma. The incidence of SCC development increases with time posttransplant. Heart and lung transplant recipients are at the highest risk of developing SCC due to more intensive immunosuppressive medications used.Squamous cell cancers of the skin in individuals on immunotherapy or who have lymphoproliferative disorders (e.g. leukemia) tend to be much more aggressive, regardless of their location. The risk of SCC, and non-melanoma skin cancers generally, varies with the immunosuppressive drug regimen chosen. The risk is greatest with calcineurin inhibitors like cyclosporine and tacrolimus, and least with mTOR inhibitors, such as sirolimus and everolimus. The antimetabolites azathioprine and mycophenolic acid have an intermediate risk profile.