INCIDENCE, RISK AND PREDICTORS OF CANCER AFTER RENAL TRANSPLANTATION; AN ANALYSIS OF ANZDATA, THE AUSTRALIA AND NEW ZEALAND DIALYSIS AND TRANSPLANT REGISTRY.

Abstract

O91* Aims: We established the magnitude of the increased risk of malignancy in renal transplant (RTx) recipients and to identified risk factors for cancer, using long-term prospectively-collected cohort data from ANZDATA. Methods: We estimated risk of cancer for all RTx in Australian and New Zealand from 1962–2003. Standardised incidence ratios (SIR) for first non-skin cancers were estimated, overall and by cancer type, for RTx after indirect standardisation by age and sex with the general Australian population using data provided by the Australian Institue of Health and Welfare (the average of national cancer statistics from years 1983–1999). Predictors of post-transplant malignancy were investigated, including age at transplantation, gender, donor source, era of transplantation and primary renal disease (PRD). Cumulative hazard estimates were calculated for each potential predictor and tested using the log-rank test. Significant univariate predictors were entered into a multivariate Cox proportional hazards model and tested using the likelihood ratio test. Interaction terms were added and results stratified by predictors demonstrating significant effect modification. Assumptions under-pinning the model were tested. Results are reported as hazard ratios (HR) with 95% confidence intervals (CI). Results: Analysis included 13410 RTx, with mean follow-up of 8.3 (± 6.2) years, of whom 1389 (10.4%) had ≥1 non-skin cancer. For recipients of cadaveric grafts SIR 2.84 (2.68–3.00). This was different for men (SIR 2.56; 2.37–2.75) and women (SIR 3.25; 3.00–3.52). In univariate analysis there was a significantly increased risk of cancer with increasing age at transplantation (trend p55 years HR 1.05 (0.84–1.31). Conclusions: Men and women >55 at transplantation can expect a >25% risk of ≥1 non-skin cancer after 10 years, whereas women and men aged 35–45 at transplantation can expect a 10% and 7% risk respectively. These data are novel, hypothesis-generating, should inform patient choice, and enable clinicians to target efforts to reduce the impact of malignancy in graft recipients