Non-melanoma Skin Cancer Outcomes in Kidney Transplant Recipients Converted from Calcineurin Inhibitors to MTOR Inhibitors: a Systematic Review

Renal transplant recipients treated with calcineurin inhibitors (CNIs) are at a high risk of developing a skin cancer. Therefore, new therapeutic options such as inhibitors of the mammalian target of rapamycin (mTORi) have been studied to find treatment regimens decreasing the rate of skin cancers. This systematic review focuses on recent randomized controlled trials studying the impact of conversion from CNI to mTORi in renal transplant recipients on development of non-melanoma skin cancers (NMSC). Outcomes of analysed trials revealed that conversion from CNI to mTORi in post-transplant patients reduces the risk and delays the occurrence of NMSC. However, mTORi protective properties against NMSC are more effective in patients with a history of a single SCC compared with multiple SCCs. At the same time, conversion to mTORi is associated with more common discontinuations secondary to adverse events and also increased mortality. In conclusion, conversion to mTORi is protective against NMSC but given the high AE rates and therapy discontinuation there is a need to determine who would benefit from conversion and search for new treatment regimens including combination strategies with mTORi.