Background: Non-melanoma skin cancer (NMSC) is the most common malignancy in transplant patients. The incidence of basal cell carcinoma (BCC) is 10 times greater than in the general population, while squamous cell carcinoma (SCC) is 100 times greater. The relationship between the BCC and SCC reverses and increases according to the degree of immunosuppression and sun exposure. One way to predict the risk of NMSC should be based on factors such as: total sun burden factor (TSB).
Objective: To determine the influence of various risk factors in the development of NMSC and its relation to the type and duration of immunosuppressive treatment, type of transplant, and TSB.
Methods: We worked with a fledgling historical cohort in which patients with kidney or liver transplant were identified and recorded if they developed some form of skin cancer. To study the factors associated with NMSC, we resorted to the strategy of a case-control study. Dermatological examination was performed and a questionnaire of risk factors made in both groups.
Results: Of the 140 patients enrolled, 51 were women and 89 men, 120 were renal transplant recipients and 20 liver transplants. Of patients who developed NMSC, 100% were renal transplant recipients. The median age was 48.5 years. Most cancer patients worked outdoors. A total of 78 lesions were found in 40 NMSC patients, 59 (76%) of them were SCC, and 19 (24%) BCC; 45% of all skin cancer patients had more than one injury. The worst affected areas were those photoexposed: 60% head and neck, trunk and upper extremities 18% 50%. In 30% of patients (12/40) 22 new tumors were identified (SCC 18 and BCC 4). No lesions were identified for melanoma. In multivariate logistic regression analysis, statistically significant features were: type-based immunosuppressive regimen of cyclosporine A, azathioprine and prednisone (OR: 59.7; 95% CI: 10.2-348), TSB > 10 (OR: 19; 95% CI: 3-120) and duration of use of immunosuppressive therapy (OR: 1.06; 95% CI: 0.9-1.1). The mean time from transplantation to first dermatological assessment was six years (+5.4). Of the patients, 93% had not regularly used sunscreen before and after transplantation.
Conclusions: The dermatological assessment is convenient and easy to perform. Primary prevention, close monitoring, diagnosis, and treatment of skin lesions are essential components of a comprehensive program for the evaluation of transplant recipients, the purpose of which is to reduce the incidence and morbidity associated with cancer.