ABSTRACT
BACKGROUND: The incidence pattern of malignancy after kidney transplantation is different from that of the general population. Because increased exposure to immunosuppressants results in an increased incidence of malignancy, institutional reports that do not consider duration of immunosuppression have limited value for providing future kidney recipients with the actual risk for malignancy or for developing a kidney allograft recipient surveillance program. Thus, we retrospectively analyzed our institutional data with regard to the duration of exposure to immunosuppressants. METHODS: A total of 757 patients who had kidney transplantation and were followed-up for at least 6 months at our hospital were reviewed retrospectively. The crude incidence rate (CI) was calculated by counting the days of exposure to immunosuppressants. RESULTS: Most malignancies after kidney transplantation were solid tumors (85.3%). The CI of malignancies was 641.1 in allograft recipients and 329.6 in the general population per 100,000 persons per year. Solid tumor cancers of the stomach, liver, lung, breast, cervix, and pancreas showed an increased CI in the allograft recipient group than the general population but cancers of the thyroid and colon did not. Based on the type of immunosuppressive agent, the CI was highest in the cyclosporine group (866/12 months/100,000 persons) than the other groups. CONCLUSIONS: We have provided the CIs of cancers after kidney transplantation at our institute. The pattern of post-transplant malignancy is different from that of western countries. Nationwide registration is needed to provide a more rational approach to post-transplant cancer surveillance in Korea.