De novo cancer avoidance after renal transplantation: A case–control study on low-dose sirolimus combined with a calcineurin inhibitor

Background/purposeFull-dose sirolimus (SRL) therapy without a calcineurin inhibitor (CNI) reduces the incidence of malignancy after renal transplantation, but with significant side effects. We hypothesized that de novo therapy with low-dose SRL combined with a CNI could still prevent cancer in renal transplant recipients.MethodsA retrospective case–control study was performed to assess the cancer incidence among renal transplant patients who had undergone surgery in our transplant centers between January 2000 and June 2012. Patients who received low-dose SRL and a CNI (SRL group, n = 189) were compared with patients receiving conventional CNI-based therapy in the same hospitals (Conventional group, n = 271).ResultsThe 5-year graft and patient survival rates were comparable between the two groups. Seven patients in the SRL group and 24 patients in the Conventional group developed malignancies during mean follow-up periods of 68.2 ± 37.5 months and 81.7 ± 51.4 months, respectively. The cancer incidence at 5 years was significantly lower in the SRL group (1.9%), than that in the Conventional group (6.7%; p = 0.04). By multivariate analyses, SRL therapy (p = 0.04), male sex (p = 0.04), and younger age (p = 0.01) were significantly associated with a lower risk of malignancy after kidney transplantation.ConclusionDe novo therapy with low-dose SRL combined with a CNI was associated with reduced risk of post-transplant cancer in renal transplant recipients. De novo cancer prevention using a low-dose proliferation signal inhibitor such as SRL could be effective for renal transplant recipients.