Cancer survival in kidney transplant recipients in Ireland

Transplantation is a well-known risk factor for malignancy. However, outcomes of cancer in transplant recipients compared with non-transplant recipients are less well studied. We aim to study the survival in kidney transplant recipients who develop cancer and compare this with cancer outcomes in the general population.We linked data from the National Cancer Registry Ireland with the National Kidney Transplant Database. The period of observation was from 1 January 1994 until 31 December 2014. Transplant recipients were considered at risk from the time of diagnosing cancer. We administratively censored data at 10 years post-cancer diagnosis. Survival was compared with all patients in the general population that had a recorded diagnosis of cancer.There were 907 renal transplant recipients and 426679 individuals in the general population diagnosed with cancer between 1 January 1994 and 31 December 2014. In those with non-melanoma skin cancer, the hazard ratio (HR) for 10-year, all-cause mortality [HR = 3.06, 95% confidence interval (CI) 2.66-3.52] and cancer-specific mortality (HR = 3.91, 95% CI 2.57-5.96) was significantly higher among transplant recipients than the general population. Patients who developed non-Hodgkin lymphoma (HR = 2.89, 95% CI 1.96-4.25) and prostate cancer (HR = 4.32, 95% CI 2.39-7.82) had increased all-cause but not cancer-specific mortality. Colorectal, lung, breast and renal cell cancer did not show an increased risk of death in transplant recipients.Cancer-attributable mortality is higher in kidney transplant recipients with non-melanoma skin cancer compared with non-transplant patients. The American Joint Committee on Cancer staging should reflect the increased hazard of death in these immunosuppressed patients.