Postrenal transplant malignancy: Incidence, risk factors, and prognosis

The newer and potent immunosuppressive agents have successfully reduced the risk of rejection after kidney transplantation, but the development of cardiovascular diseases, infections, and malignancy is major factors limiting their success. Posttransplantation malignancy is the second most common cause of death in renal transplant recipients after cardiovascular disease; it is expected that mortality due to malignancy may become the most common cause of death within the next two decades. This study is designed to evaluate the incidence, risk factors, and types of malignancies occurring after renal transplantation and their impact on patient and graft survival. A total of 2288 patients underwent living donor renal allotransplantation in the Urology and Nephrology Center, Mansoura University, during the period between 1975 and 2011. Among these patients, 100 patients developed posttransplantation malignancy. Patients were categorized into five major groups according to their type of malignancy; Kaposi's sarcoma (KS), non-Kaposi's skin tumors (non-KS), posttransplant lymphoproliferative disorders (PTLD), solid tumors, and genitourinary and reproductive system (GU and RS). Overall, the incidence of cancer in renal transplant recipients was 4%. There were 83 male (83%) and 17 female patients (17%). The most frequent cancer was KS seen in 33 patients (33%). The lowest median time to development of cancer was observed in KS (35 months). The highest median time to development of cancer was observed in PTLD (133 months). The best graft survival was observed in PTLD and the worst in non-KS tumors. The best patient survival was observed in KS and the worst in GU and RS tumors. Azathioprine-based regimen was associated with a higher rate of cancer. The number of patients who died was 65 (65%). Our results indicate that the occurrence of malignancy has an important impact on short- and long-term graft and patient survival.