De novo malignancies after kidney and liver transplantations: experience on 582 consecutive cases.

De novo malignancies after transplantation are a growing problem of solid organ transplant recipients, due to longer survival follow-up under chronic immunosuppression. The aim of this study was to analyze a population of 582 consecutive kidney (n = 382) and liver (n = 202) transplant recipients, who survived at least 12 months after transplantation, at a single transplant center for the development of de novo cancers. The incidence of de novo malignancies was 7% after both renal and liver transplantation. The median elapsed time from transplant to the diagnosis of de novo malignancy was 45 months (range 3 to 220) months for kidney and 37 months (range 12 to 101 months) for liver transplants. Skin cancers were the most common within renal recipients, while gastroenteric cancers were more frequently encountered in liver transplants. Oropharyngeal and upper digestive tract tumors were always associated with a history of chronic alcohol consumption in liver recipients. Liver transplant recipients treated for acute rejection had a worse cancer prognosis than patients without rejection 1- and 2-year survivals 83% and 63% versus 36% and 17% (P = .026). The estimated 1- and 2-year survival rates for all types of de novo malignancies were 79% and 66%, including 64% and 51% for solid organ tumors versus 89% and 89% for skin cancers and posttransplant lymphoproliferative disorder (PTLD) (P = .17) in renal transplants and 70% and 42%, including 57% and 28% for solid organ tumors versus 85% and 64% for skin cancers and PTLD (P = .43) in liver transplants respectively.