Risk of Kidney Failure in Patients With Cancer: A South Korean Population-Based Cohort Study.

Rationale & Objective: Reduced kidney function is associated with an increased risk of cancer; however, it is unclear if cancer increases the risk of kidney failure with replacement therapy (KFRT). We assessed the risk of KFRT among patients with various types of cancer collectively and with specific types of cancer.
Study Design: Retrospective population-based cohort study.
Setting & Participants: A total of 2,473,095 participants with (n = 824,365) or without (n = 1,648,730) cancer registered in the Korean National Health Insurance Service database.
Predictors: Cancer and cancer subtypes defined using International Classification of Diseases, 10th Revision, Clinical Modification, codes.
Outcomes: Primary outcome was KFRT defined as the initiation of hemodialysis or peritoneal dialysis or kidney transplantation.
Analytical Approach: For each patient with cancer, 2 controls matched for age, sex, estimated glomerular filtration rate, diabetes, and hypertension were included. To address the competing risk of death, a competing risk survival analysis was conducted using the Fine and Gray method.
Results: Occurrence of KFRT was higher in patients with cancer than in controls without cancer (incidence rates of 1.07 vs 0.51 cases per 1,000 person-years). Competing risk analysis showed that cancer was significantly associated with an increased risk of KFRT after adjusting for other potential predictors (adjusted hazard ratio, 2.29 [95% CI, 2.20-2.39]). Multiple myeloma, leukemia, lymphoma, and kidney, ovarian, and liver cancer were most significantly associated with an increased KFRT risk, with multiple myeloma conferring the highest risk across age and sex groups. All subgroups of patients with cancer (based on age, sex, smoking, alcohol, exercise, obesity, and comorbid conditions) exhibited a higher risk of KFRT.
Limitations: Causal association between cancer and kidney outcomes could not be confirmed.
Conclusions: Patients with cancer, particularly those with multiple myeloma, exhibited an increased risk of KFRT after accounting for the competing risk of death.
(Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)