Sirolimus use improves cancer-free survival following transplantation: A single center 12-year analysis

Abstract

Background: Sirolimus, is used in ~5% of all US transplant centers as part of a maintenance immunosuppression regimen following solid organ transplantation. In previous published results, we showed that the use of a Sirolimus-based, early steroid withdrawal immunosuppression regimen improved patient and graft 10-year survival. In this study, we aimed to determine whether long-term Sirolimus use is also associated with improved cancer-free survival following renal transplantation. Materials and Methods: From 2003 to 2015, 563 kidney transplant recipient had steroids discontinued by post-operatively and maintained on Sirolimus, Tacrolimus [Tac], and Mycophenolate Mofetil [MMF]. We compared cancer-related outcomes with that of our 65 historical controls maintained on Tac, MMF and steroids. Rates of pre- and post-transplant malignancies were determined. Additionally, Kaplan–Meier survival curves were constructed to determine patient and cancer-free survival. Results: Patients maintained on chronic immunosuppression with Sirolimus developed statistically-significant lower levels of post-transplant lymphoproliferative disease (PTLD, 5.88% vs. 0.5%; p < 0.05) with no difference in rates of other post-transplant malignancies. Cancer-free survival as well as cancer-free mortality were also improved 10–12 years post-transplant (p = 0.05, p < 0.05). However, long-term patient survival was equivalent in both cohorts (p = 0.22). Conclusion: Sirolimus-based immunosuppression regimens improve long-term cancer-free survival while maintaining equivalent patient and graft survival. Keywords: Sirolimus, Post-transplant malignancy, Renal transplant, Transplant outcomes