Background: Conversion from calcineurin inhibitors (CNI) to sirolimus (SRL) is an option for renal transplant patients who develop a tumor. This strategy, however, may be associated with an increased risk of rejection.
Aim: We sought to evaluate a series of renal transplant patients who underwent conversion from CNI to SRL because they developed a tumor during the posttransplant period.
Methods: This prospective study of 29 patients included 2 patients with skin cancer (1 melanoma and 1 squamous cell carcinoma) and 27 patients who developed other tumors: lung (n = 6), prostate (n = 4), lymphoma (n = 2), colon adenocarcinoma (n = 2), kidney (n = 2), Kaposi sarcoma (n = 2), urothelium (n = 1), parotid (n = 1), larynx (n = 1), gastric (n = 1), breast (n = 1), tongue (n = 1), liver (n = 1), xanthoastrocytoma (n = 1), and aggressive angiomyxoma of the perineum (n = 1).
Results: CNI were withdrawn in 28 patients and reduced in the remaining patient. Renal function was better when CNI were rapidly or abruptly suspended, with maintenance of cyclosporine (CsA) + SRL for more than 3 months being especially detrimental. Proteinuria worsened in patients whose preconversion levels were >0.5 g/d, particularly those treated with CsA. There was no episode of rejection.
Conclusions: SRL is a promising option for the management of posttransplant tumors. The switch in immunosuppression should be undertaken quickly, especially in patients under treatment with CsA.