Neoplasia in kidney transplant recipients

De novo malignant tumors have been associated with the use of immunosuppressive agents in treatment of organ transplant recipients. A direct causative effect of these agents has not been proved clinically or experimentally. The Denver Transplant Tumor Registry, reported by Penn [I], has compiled records of de novo cancers in 184 organ homograft recipients; however, these reports are submitted voluntarily and may not reflect the actual incidence in the large number of transplants being performed. The current (Twelfth) American College of Surgeons/National Institutes of Health Transplant Registry reported that over 16,000 kidney transplantations have been performed in the world. During the past four years we have observed six neoplasms in therapeutically immunosuppressed kidney transplant recipients. This report presents our observations and reviews current theories of possible etiologic associations.