Impact of Pre-Transplant Malignancy on Outcomes After Kidney Transplantation: United Network for Organ Sharing Database Analysis

Abstract

Kidney transplant recipients with a history of a pre-transplant malignancy (pre-TM) have an increased risk of post-transplant malignancies (post-TM) and suspected inferior long-term outcomes. No large database studies have examined modern day trends and outcomes in this patient population compared with those without a pre-TM. The United Network for Organ Sharing (UNOS) database was queried for primary adult kidney transplant recipients with pre-TM. Outcomes were compared in patients with and without pre-TM from 2004 to 2016 using multivariable Cox proportional hazard analyses (n= 170,684). The rate of kidney transplants in patients with pre-TM increased from <1% of all kidney transplants in 1994 (n= 77) to 8.3% in 2016 (n= 1,329). Pre-TM was associated with development of post-TM (hazard ratio [HR] 1.77 CI 1.68, 1.86), all cause (HR 1.22 CI 1.18, 1.27), and death-censored graft failure (HR 1.08 CI 1.02, 1.15) between 2004 and 2016. The 5-year all cause graft failure rate was 28% for pre-TM patients and 22% for non-pre-TM patients. Pre-TM was associated with decreased patient survival (5-year 80% vs 88% and HR 1.23 CI 1.18, 1.28). Of the deceased, more pre-TM patients died of malignancy (19% vs 11%). Increasing numbers of patients with pre-TM are undergoing kidney transplantation. This analysis indicates that patients with pre-TM are at increased risk of post-TM, graft loss, and decreased overall survival. The study's limitations highlight the need for collaborative database development between transplant and cancer registries to better define the inter-relationship between a pre-TM and cancer survivorship vs freedom from prolonged dialysis.