CANCER INCIDENCE IN 854 KIDNEY-TRANSPLANT RECIPIENTS FROM A SINGLE INSTITUTION - COMPARISON WITH NORMAL POPULATION AND WITH PATIENTS UNDER DIALYTIC TREATMENT

In this retrospective historical study, we compared the incidences of malignancies observed among 854 renal transplant recipients (RT) with at least 1 yr of follow-up, with the incidences of neoplasias among pa tients under regular dialytic treatment (RDT) and a control population from Northern Italy. Cox's proportional hazard model was used in RT r ecipients in order to evaluate the prognostic factors related to the d evelopment of neoplasia. Seventy six out of 854 RT patients (8.9%) dev eloped some malignant neoplasia: 46% of these 76 were cutaneous neopla sias including melanomas, and the remaining 54% non cutaneous cancers: 33% miscellaneous tumors (MT), mostly adenocarcinomas, 17% Kaposi's s arcomas (KS), 4% non-Hodgkin's lymphomas (NHL). Malignancies had a hig her incidence (p<0.01) among RT recipients than among control and RDT patients. However, MT were equally frequent among the three groups. RD T patients on the contrary, had similar incidence of neoplasias when c ompared to the control population, but showed a lower incidence of squ amous cell carcinomas (SCC). The risk ratios (RR) for the most frequen t neoplasias among RT recipients vs. control population were: 224.7 fo r KS, 7.4 for NHL, 6.2 for SCC, 5.7 for basal cell carcinomas (BCC), 4 .0 for MT. The risk of developing a de novo neoplasia was of about 13% at 10 yr and of 34% at 20 yr. In RT recipients, Cox's proportional an alysis showed that age >40 at transplantation and male sex were the on ly risk factors associated with an increased incidence of neoplasias, while no difference was observed between conventional (azathioprine+me thylprednisolone: Aza+MP) and. CsA therapy or in CsA monotherapy vs. d ouble or triple therapy. However, KS occurrence correlated both with C sA dose (RR 15.2 for monotherapy; 12.5 for double therapy; 2.98 for tr iple therapy) and with 10 or more i.v. methylprednisolone pulses for t reatment of rejection (RR 5.2). We conclude that in our series CsA doe s not: increase the risk for development of neoplasias, when compared to conventional immunosuppression.