Overall and Site-Specific Cancer Mortality in Patients on Dialysis and after Kidney Transplant

Significance Statement Patients with ESRD experience a substantially increased incidence of cancer, but few studies have examined patterns of cancer mortality among such patients. This population-based cohort study of Australian patients who initiated dialysis or received a kidney transplant from 1980 to 2014 found that the risk of cancer-related death among 52,936 patients on dialysis and 16,820 kidney transplant recipients was 2.5 times higher than that of age- and sex-matched controls in the general population. For patients on dialysis, increased cancer mortality is primarily from cancers that caused ESRD; among transplant recipients, the increase is largely due to de novo cancers. Additional efforts are required to clarify factors and mechanisms involved in increased cancer risk and to improve early detection and management of cancer in this population. Background Patients with ESRD have a substantially increased cancer risk, but few studies have examined the patterns of cancer mortality along a patient's journey from dialysis to transplantation. Methods We identified all Australian patients on dialysis and patients with transplants from 1980 to 2014 from the Australia and New Zealand Dialysis and Transplant Registry. Using standardized mortality ratios (SMRs), we compared cancer mortality among patients on dialysis and patients with transplants versus the general population (overall and by age, sex, year, and site); we also performed a subgroup analysis excluding patients with preexisting cancers. Results We followed 52,936 patients on dialysis and 16,820 transplant recipients for 170,055 and 128,352 patient-years, respectively. There were 2739 cancer deaths among patients on dialysis and 923 cancer deaths among transplant recipients. Overall, cancer SMRs were 2.6 for patients on dialysis and 2.7 for transplant recipients. For patients on dialysis, SMRs were highest for multiple myeloma (30.5), testicular cancer (17.0), and kidney cancer (12.5); for transplant recipients, SMRs were highest for non-Hodgkin lymphoma (10.7), kidney cancer (7.8), and melanoma (5.8). Some 61.0% of patients on dialysis and 9.6% of transplant recipients who experienced cancer death had preexisting cancer. The SMRs for de novo cancer was 1.2 for patients on dialysis and 2.6 for transplant recipients. Conclusions Patients on dialysis and transplant recipients experienced >2.5-fold increased risk of cancer death compared with the general population. This increased risk was largely driven by preexisting cancers in patients on dialysis and de novo cancers in patients with transplants.