Prostate Cancer, Kidney Transplant Wait Time, and Mortality in Maintenance Dialysis Patients: A Cohort Study Using Linked United States Renal Data System Data

Abstract Rationale and Objective Impact of prostate cancer on mortality in patients with end stage kidney disease (ESKD) may be different from the general population. Prostate cancer may also delay kidney transplantation but has not been studied in a population based cohort. We examined how prostate cancer influenced time to kidney transplant and death in dialysis population. Study Design Retrospective population based risk-set propensity score matched cohort study. Setting and Participants Men, 40-79 years old, who were dialysis dependent, Medicare beneficiaries, without prior documented prostate cancer, from the United States Renal Data System. Exposures Incident prostate cancer, identified using International Classification of Disease, ninth version, Clinical Modification system diagnosis code, 185. Outcomes Time to kidney transplant and death. Analytical Approach Propensity based risk-set matching to reduce bias between cases and controls. Cox-propotional hazards model for time to death and Fine-Gray competing risk model for time to kidney transplant. Results Among a total of 588,478 male dialysis patients who met our eligibility criteria, 18,162 had claims for prostate cancer. After propensity based risk-set matching, there were 15, 554 pairs of prostate cancer cases and controls. Among the matched pairs, survival rates were 76%, 48%, and 30% at 1, 3, and 5 years in the prostate cancer group, compared to 80%, 51%, and 33% in the control group with a relative mortality of 95%, 94%, and 91% respectively (log-rank test p-value Limitations Retrospective registry study Conclusions Prostate cancer is associated with modest increases in risk of death and time to transplant in ESKD patients. Kidney transplant is associated with the same degree of survival benefit among those with pretransplant prostate cancer as those without.