Incidence and risk factors for development of malignant neoplasia after feline renal transplantation and cyclosporine-based immunosuppression.

The objective of this retrospective study is to report and analyse the incidence of and risk factors for post-transplant malignant neoplasia (PTMN) in feline renal transplant recipients (cases, n = 45) and compare incidence to a population of cats that did not receive a transplant (controls, n = 79). Information from the medical records of cases regarding signalment, blood work and concomitant disease, post operative cyclosporine concentrations, survival time (ST), and whether PTMN developed, the type of PTMN, time to occurrence (TTO), and ST after diagnosis was gathered. PTMN occurred in 11 of 45 (24%) cases, of which, four were lymphoma. Median TTO of all PTMN was 1020 days. Median TTO of lymphoma was 454 days. Median ST after diagnosis of PTMN was 15 days. No risk factors were identified. Compared with control cats, cases had more than six times higher odds of developing PTMN compared with control cats (P < 0.01).