Sirolimus for Secondary Prevention of Skin Cancer in Kidney Transplant Recipients: 5-Year Results

Purpose Transplant recipients who develop cutaneous squamous cell carcinomas are at high risk for multiple subsequent skin cancers. Sirolimus has been shown to reduce the occurrence of secondary skin cancers, but no study included a follow-up exceeding 2 years. We extended at 5 years the TUMORAPA randomized trial of sirolimus-based immunosuppressive regimen versus calcineurin inhibitor-based immunosuppression. Methods Kidney transplant recipients receiving calcineurin inhibitors who had at least one cutaneous squamous cell carcinoma were randomly assigned to receive sirolimus as a substitute for calcineurin inhibitors (n = 64) or to maintain their initial treatment (n = 56). The primary end point was survival free of squamous cell carcinoma at 5 years. Secondary end points included the occurrence of other skin cancers, renal function, patient and graft survival, and treatment tolerance. Results Survival free of cutaneous squamous cell carcinoma was significantly longer in the sirolimus group than in the calcineurin inhibitor group ( P = .007). In the sirolimus group, the number of patients with new skin cancers was significantly lower compared with the calcineurin inhibitor group: 22% versus 59% for squamous cell carcinomas ( P < .001), 34% versus 66% for other skin cancers ( P < .001), and 20% versus 37.5% for basal cell carcinomas ( P < .05). Kidney graft function, patients, and graft survival were similar in both groups. In the sirolimus group, the mean number of serious adverse effects per patient decreased from 1.16 during the first 2 years, to 0.83 between years 2 and 5. Conclusion In kidney transplant recipients with previous cutaneous squamous cell carcinomas, the antitumoral effect of conversion from calcineurin inhibitors to sirolimus was maintained at 5 years, and sirolimus tolerance was satisfactory.