Non-melanoma skin cancer in Portuguese kidney transplant recipients - Incidence and risk factors

Background: cancer is currently among the three leading causes of death after solid organ transplantation and its incidence is increasing. non-melanoma skin cancer - squamous cell carcinoma and basal cell carcinoma - is the most common malignancy found in kidney transplant recipients (ktrs). the incidence of non-melanoma skin cancer in ktrs has not been extensively studied in portugal. objectives: to determine the incidence of non-melanoma skin cancer in ktrs from the largest portuguese kidney transplant unit; and to study risk factors for non-melanoma skin cancer. methods: retrospective analysis of clinical records of ktrs referred for the first time for a dermatology consultation between 2004 and 2013. a case-control study was performed on ktrs with and without non-melanoma skin cancer. results: we included 288 ktrs with a median age at transplantation of 47 years,a male gender predominance (66%) and a median transplant duration of 3.67 years. one fourth (n=71) of ktrs developed 131 non-melanoma skin cancers,including 69 (53%) squamous cell carcinomas and 62 (47%) basal cell carcinomas (ratio squamous cell carcinoma: basal cell carcinoma 1.11),with a mean of 1.85 neoplasms per patient. forty percent of invasive squamous cell carcinomas involved at least two clinical or histological high-risk features. the following factors were associated with a higher risk of non-melanoma skin cancer: an older age at transplantation and at the first consultation,a longer transplant duration and the presence of actinic keratosis. ktrs treated with azathioprine were 2.85 times more likely to develop non-melanoma skin cancer (p=0.01). conclusion: non-melanoma skin cancer was a common reason for dermatology consultation in portuguese ktrs. it is imperative for ktrs to have access to specialized dermatology consultation for early referral and treatment of skin malignancies. © 2016 by anais brasileiros de dermatologia.