Incidence and Long-Term Prognosis of Cancer After Kidney Transplantation

Background: Malignancy is an important cause of mortality in renal transplants recipients. The incidence of cancer is increased by immunosuppressive treatment and longer kidney graft survival. The aim of this study was to evaluate the incidence, prognosis and survival of posttransplant malignancies: solid organ cancer (SOC), posttransplant lymphoproliferative disorder (PTLD), and nonmelanoma skin cancer (NMSC).

Methods: We retrospectively studied the development of cancers among kidney transplants patients in our hospital from January 1979 to January 2015. We analyzed demographic and clinical characteristics, risk factors, and patient survival after tumor diagnosis.

Results: We included 1450 kidney transplants recipients with a mean follow-up was 10 years; among them, 194 developed malignancies. The mean age at presentation was 59 ± 10 years. The SOC, PTLD, and NMSC incidences were 6.2%, 1.2%, and 6%, respectively. The most common tumors were kidney (16.6%), colon (11%), bladder (10%), breast (10%), prostate (10%), and lung (8.8%). The median times to development of a SOC, PTLD, and NMSC were 6.86 (range, 3.7-12), 4.43 (range, 1.8-5.7), and 8.19 (range, 3.8-12.2) years, respectively. Risk factors associated with developing SOC and PTLD were patient age (odds ratio [OR], 1.03; P < .001) and time posttransplant (OR, 1.05; P = .02), whereas for NMSC were to be male (OR, 3.61; P < .001), to take calcineurin inhibitors (OR, 2.17; P = .034), patient age (OR, 1.05; P < .001) and time posttransplant (OR, 1.15; P < .01). The mean survival time from the diagnosis of SOC, PTLD, and NMSC were 2.09 (range, 0.1-5.3), 0.22 (range, 0.05-1.9), and 7.68 (range, 3.9-10.5) years, respectively (P < .001).

Conclusions: SOC occurs more frequently than other malignancies among renal transplant patients. NMSC has better survival and prognosis. Older patients and prolonged graft function have a greater risk of developing malignancies.