Association of chronic kidney disease with mortality risk in patients with lung cancer: a nationwide Taiwan population-based cohort study

Objective Our population-based research aimed to clarify the association between chronic kidney disease (CKD) and mortality risk in patients with lung cancer. Design Retrospective cohort study Setting National health insurance research database in Taiwan Participants All (n=137077) Taiwanese residents who were diagnosed with lung cancer between 1997 and 2012 were identified. Eligible patients with baseline CKD (n=2269) were matched with controls (1:4, n=9076) without renal disease according to age, sex and the index day of lung cancer diagnosis. Methods The cumulative incidence of death was calculated by the Kaplan-Meier method, and the risk determinants were explored by the Cox proportional hazards model. Results Mortality occurred in 1866 (82.24%) and 7135 (78.61%) patients with and without CKD, respectively (P=0.0001). The cumulative incidences of mortality in patients with and without chronic renal disease were 72.8% vs 61.6% at 1 year, 82.0% vs 76.6% at 2 years and 88.9% vs 87.2% at 5 years, respectively. After adjusting for multiple confounding factors including age and comorbidities, Cox regression analysis revealed that CKD was associated with an increased risk of mortality (adjusted HR 1.38; 95% CI 1.29 to 1.47). Stratified analysis further showed that the association was consistent across patient subgroups. Conclusion Corrrorbidity associated with CKD is a risk factor for mortality in patients with lung cancer.