The data from this study suggest that more patients develop skin malignancies than previously reported from Europe. It is important to advise patients before transplantation in regard to skin complications, provide regular dermatological follow-up, and tailor immunosuppressive regimen to minimum doses to be compatible with good graft function.

HPV DNA is widespread in normal adult skin, particularly in transplant patients. In our study, the presence of EV but not cutaneous HPV DNA in normal skin was significantly associated with NMSC status and may prove to be of predictive value for skin cancer risk. These data provide reason to focus on EV HPV types as causal agents in skin cancer.

In the Oxford transplant population studied melanomas occurred at approximately 8 times the rate in the general population. This is the highest rate reported in the literature. The patients had a better outcome than reported previously. This may be due to detection at a relatively early stage. Renal transplant recipients attend dedicated dermatology clinics in Oxford, which may have contributed to the early diagnosis and good outcome.

Glutathione S-transferase polymorphisms and skin cancer after 40% 20 years after transplantation [reviewed in 1]. The renal transplantation. majority of tumors are squamous cell carcinomas (SCCs)Background. Susceptibility to skin cancer after transplanta- [2,3], but the frequencies of basal cell carcinomas (BCCs) tion is multifactorial, and risk factors include skin type, sun and malignant melanoma are also increased [4,5]. Skin exposure, and level of immunosuppression. A major mechanism tumors frequently occur at multiple sites [2,6] and are of carcinogenesis is ultraviolet radiation-induced free radical damage, and genetically determined ability to metabolize free more aggressive in transplant recipients than in the genradicals may also predispose to skin cancer. The glutathione eral population [7]. Susceptibility to skin cancer after S-transferase enzymes play a major role in limiting the toxic transplantation is multifactorial, and the major risk fac-Key words: genetic susceptibility, skin tumor, free radical metabolism, [13,14]. The most common polymorphism is a large squamous cell carcinomas, basal cell carcinomas, UV light exposure, anti-oxidants. deletion of the GSTM1 gene, and 50% of Caucasoid are homozygous for this variant (GSTM1null) [15]. Addi-