There are currently over 150,000 solid organ transplant recipients (OTRs) living in the United States. As more transplants are performed and postoperative survival improves, the complications of chronic immunosuppression, including development of cutaneous squamous cell carcinoma (SCC), have become more prevalent.

INCIDENCE

SCC occurs in OTRs with an incidence approximately 65 to 100 times that in the general population. In contrast to the nonimmunosuppressed population in which SCC is outnumbered by basal cell carcinoma at a 1:4 ratio, SCC occurs approximately 2 to 4 times more frequently than basal cell carcinoma in OTRs, making it the most common skin cancer in these patients.

The incidence of SCC in OTRs is related to the patient's age at transplantation, gender, skin phototype, degree of pretransplant and posttransplant ultraviolet radiation (UVR) exposure, and duration and level of immunosuppression. Chronic immunosuppression contributes to increased cutaneous malignancies, with the prevalence of nonmelanoma skin cancer (NMSC) reaching 40–75% 20 years after transplantation. OTRs with lighter skin phototypes, corresponding to a tendency to burn rather than tan with sun exposure, develop SCC at a higher frequency than those with darker phototypes residing in the same geographic area. Males experience a higher incidence of SCC than females, as do patients receiving their transplants at a greater age.

Residence in a geographic location with a lower latitude, and therefore higher ambient UVR exposure, is also associated with increased rates of SCC following transplantation.