A prospective study of the incidence of skin cancer and its risk factors in a Spanish Mediterranean population of kidney transplant recipients

BACKGROUND: Skin cancer is the most common malignancy occurring in kidney transplant recipients (KTRs). OBJECTIVES: Our purpose was to investigate, prospectively, the cumulative incidence of cancerous and precancerous skin lesions as well as their risk factors in a close follow-up population of KTRs from a Mediterranean area of Spain. PATIENTS AND METHODS: One hundred and seventy-four consecutive KTRs were examined at the moment of transplant and then at 6-month intervals. The cumulative incidence of skin cancer was computed. To analyse the role of potential risk factors (age at transplantation, cause of renal failure, duration of pretransplant dialysis, type of immunosuppressive regimen, sun-reactive skin type and history of occupational sun exposure), the Cox regression method was used. RESULTS: After a median follow-up of 72 months (range, 12-140), 39 patients (25.3%) developed 142 tumours [84 basal cell carcinoma (BCC) and 58 squamous cell carcinoma (SCC)]. The BCC/SCC ratio was 1.4 : 1. The cumulative incidence for skin cancer was 13% after 3 years of graft survival, increasing to 27.5% at 6 years and 48% at 10 years. Only age at the time of transplantation and occupational sun exposure had statistical significance as risk factors (P < 0.001). CONCLUSIONS: Our study confirms the high incidence of non-melanoma skin cancer among KTRs in a Mediterranean population with occupational sun exposure and the patient's age at the time of transplantation being the main risk factors. We believe that all organ transplant programs should provide educational information about protecting oneself from the sun as well as include follow-up visits by dermatologists in order to facilitate early diagnosis and treatment of skin cancer.