18. Tumors After Renal Transplation

TUMORS AFTER RENAL TRANSPLANTATION

• Overall incidence of cancer: 6% (4-18%)
• Incidence of tumors increases dramatically with time after transplantation
• The most frequent encountered tumors: skin SCCs, NHLs, KSs, in situ carcinomas of the uterine cervix, carcinomas of the vulva and perineum, hepatobiliary carcinomas, sarcomas
• The percentage of lymphomas (PTLD) within malignant tumors is 16-22% vs 5% in general population. Among patients given OKT3 lymphomas comprise the 54% of all tumors.
• Incidence increases parallel to the intensity of immunosuppressive therapy.
• The incidence of PTLD is higher in heart than renal transplants
• Lymphomas appear at an average of 32 months (1-254)
• Among lymphomas:
  • Hodgkin's disease: 2.5%
  • NHLs: 93% vs 65% in general population
  • Myelomas: 4%
• Incidence of NHLs is increased 29-40 fold over that seen in age-matched controls
• Among NHLs:
  • 88% are of B-cell origin: frequently immunoblastic or large cell
  • 12% are of T-cell origin
  • 51% :multiple organ involvement
  • 49%: single organ involvement
  • 70% showed extranodal site involvement vs 24-48% in general population
• NHLs are thought to be EBV-induced, impairment of surveillance mechanisms, chronic antigenic stimulation by the allograft, viral oncogenesis, direct action of immunosuppresants
• 2 types of lymphomas:

  early onset: within the 1st year

  children or young adults (23 y)

  presentation with IMNL syndrome

  cyclosporine

  response to conservative treatment

  late onset: older age (48 years)

  localized mass

  poor outcome