Switching to Sirolimus Monotherapy for De Novo Tumors After Liver Transplantation. A Preliminary Experience

Background/Aims: Alcoholic cirrhosis, smoking, and use of calcineurin inhibitors (CNI) are associated with the development of de novo tumors in liver transplant (LT) recipients. Sirolimus is an immunosuppressor with antitumoral properties. Methodology: Between April 1986 and April 2007, we performed 1231 liver transplants in 1084 recipients. A total of 128 de novo tumors were observed in 116 recipients from a sample of 850 adult recipients who survived more than 2 months. This study comprises 16 LT recipients (13 male and 3 female; mean age, 45.1 +/- 11.1 years) who were switched to sirolimus monotherapy who developed de novo tumors and were switched from CNI or mycophenolate mofetil to sirolimus monotherapy. Results: De novo tumors location: 2 lymphomas, 9 upper aerodigestive, 1 skin, 1 parotid, 1 lung, 1 breast, and 1 rectum. Time from LT to sirolimus monotherapy was 86 months; time taking to switching from CNI to sirolimus monotherapy was 48 days, and mean follow-up of patients on sirolimus monotherapy was 15.7 months. Thirteen patients underwent tumor resection, 5 received chemotherapy, and 5 received radiotherapy. Five patients died during the follow-up, and patient survival after diagnosis was 42.8 months. Mean dose of sirolimus was 2.7mg/day and the mean trough level was 8.9ng/mL. Total cholesterol and triglycerides values increased after switching. Mean serum creatinine, glucose, AST and ALT values, and haematological parameters were similar before and after switching. No patients developed acute rejection, and adverse effects were observed in 8 patients. Conclusions: Sirolimus monotherapy can be used safely to improve survival in LT recipients with de novo tumors.