Effect of immunosuppression for primary renal disease on the risk of cancer in subsequent renal transplantation: a population-based retrospective cohort study.

Background: To measure the risk of cancer in renal transplantation for recipients who had previously been treated with immunosuppressive agents for primary renal disease.

Methods: A retrospective population-based cohort study of 5970 renal transplant recipients in Australia registered on the Australia and New Zealand Dialysis and Transplant Registry between 1982 and 1997 and followed until 2007. Data about the incidence of a range of cancer types from this Registry were compared with cancer incidence data for the general population matched for cancer type, year of incidence, age, and gender derived from national cancer records. Outcome measures for each cancer group with or without pretransplantation immunosuppression were cancer-specific standardized incidence ratios and a multivariate hazard ratio (HR) standardized to 1.

Results: For those treated with pretransplantation immunosuppression, the risks for four cancer groups during renal transplantation were significantly increased: anogenital cancer (HR, 3.13; confidence interval [CI], 1.92-5.11; P<0.0001), non-Hodgkin's lymphoma (HR, 2.37; CI, 1.53-3.68; P=0.0001), breast cancer (HR, 2.52; CI, 1.13-5.61; P=0.024), and urinary tract cancer (excluding kidney) (HR, 1.84; CI, 1.13-3.01; P=0.015). However, the risks of cancer in the oral cavity and pharynx, kidney, thyroid, colon, leukemia, lung, melanoma, prostate, and stomach were not significantly increased.

Conclusions: Pretransplantation immunosuppression for primary renal disease increases the risks of four cancer types in renal transplantation while sparing the others. Patients in whom this treatment is being considered should be informed of these risks.