INTRODUCTION

Skin cancer is the most common malignancy in the western world. National Registries containing information on both malignant melanoma (MM) and nonmelanoma skin cancers (NMSCs), including basal cell carcinomas, demonstrate that malignancies of the skin account for over 1/3 of all malignancies. Skin cancers occur more frequently in organ transplant recipients (OTR) relative to the general population. Although there is a documented increase in several solid organ malignancies following transplantation, it is in the skin we see the most dramatic increase in cancer. Transplant recipients are at particularly high risk of squamous cell carcinoma (SCC), with up to a 100-fold increase in the relative risk when compared with the nontransplanted population. This compares with a 10- to 16-fold increase in basal cell carcinoma (BCC) for renal transplant recipients. Within 20 years of transplantation, approximately 40–50% of Caucasian patients in most western countries and 70–80% of Caucasian Australians will have developed at least one NMSC. An increased incidence of melanoma in transplant patients has been reported but other studies have failed to confirm these findings. Small cohort size and failure to standardize data for age and sex may explain some of the nonsignificant studies. In many studies, almost all patients with melanoma are male, in part a consequence of the fact that two thirds of the population with renal transplants are male. Other types of skin cancer associated with immunosuppression in transplant patients include Kaposi's sarcoma and Merkel cell carcinoma.