Skin Cancer and Immunosuppression Type in Long-Term Renal Transplant Recipients: A Case-Controlled Analysis.

Abstract

Introduction: Renal transplant recipients are 3 times more likely to develop skin cancer (SC) when compared to age-matched general populations, and this is associated with increased morbidity and mortality. The reason underpinning the increased prevalence in this group most probably relates to treatment with immunosuppression (IS), however the association is not yet fully understood. Objectives: To determine the prevalence of SC in our long-term kidney transplant recipients. To assess whether SC prevalence is related to the type of IS taken by this patient cohort. Methods: We collected data from a retrospective cohort of all (n= 335) long-term (> 8 years) kidney recipients attending our annual review transplant clinic between 2010-2013. We documented the total number of SCs, time to development of first SC post transplantation and IS treatment. For the analysis of IS as risk factor, patients with SC were matched to an equal number of controls in age, total years from first transplant and skin type criteria. McNemar's test was used to test the effect of IS on risk of SC. Results: 67 (21%) patients had at least one SC. In these a total of 281 basal cell carcinomas, 157 squamous cell carcinomas, 4 melanomas and 1 Kaposi's sarcoma were diagnosed. The average time to development of a SC was 13 years (range 2-32 years) after transplant. There were no statistically significant differences between case and control patients in the proportion of patients taking any of the IS drugs one year before the first SC. However the difference in the proportion of patients who developed SC after taking azathioprine, compared to controls, is borderline significant.Table: No Caption available.Conclusion: We have identified a high prevalence of SC in our long-term kidney transplant patients. In our analysis we found that prevalence was not significantly related to the type of IS taken, although preliminary results point to azathioprine as a risk factor, and tacrolimus as protective. Further work to determine the relevance of cumulative IS dose is warranted.